# data[].attributes.attachment_link.title
Neuromodulatory pathways in learning and memory: Lessons from invertebrates

# data[].attributes.headline
The Relationship Between Neurotransmitters & Its Effects on Education

# data[].attributes.subject
The Relationship Between Neurotransmitters & Its Effects on Education

# data[].attributes.body
The article attached with the post highlights how the embracement of new pedagogical methods and techniques can have an impact on how neurotransmitters can remain active, where effective stimulation can lead to the creation of new neural connections while pruning out old and weak connections, thus ensuring each students brain is developed in ways that are developmentally appropriate.

—Austin Nicholas Dragoș [United States of America]

# data[].attributes.attachment_link.readable_text
Abstract

One would hope that of the many ways to conceptualize teaching and learning, scientists would view these processes as driving biological changes in the brain. Here, the authors draw connections between innovative teaching techniques and neuroscience that may support our understanding of why innovative teaching is so effective at promoting learning.

How do you conceptualize learning? Do you think of learning as a contractual agreement: the instructor performs certain actions to facilitate learning, and the student, in turn, explicitly or implicitly promises to behave in ways to receive that learning? Or do you think of learning in sociological terms: the learner, through what he or she learns, transforms his or her beliefs and becomes a more emancipated citizen of the world? Or perhaps you think of learning in psychological terms: learners are motivated, store facts in their minds, and create mental knowledge structures. All of these ways of conceptualizing learning can be beneficial in understanding how students learn and what makes teaching effective.

However, at their most fundamental and mechanistic level, teaching and learning are neurological phenomena arising from physical changes in brain cells. The notion that learning and memory are neurobiological processes is relatively young, dating back only to the 18th century ( Hartley, 1749 Herculano-Houzel, 2002 Deligiannidi and Howard-Jones, 2015 ; ). Nevertheless, recent advances in brain science have given us an in-depth picture of the molecular and cellular changes that occur during learning, and the consensus of neurobiologists is that these alterations are both necessary and sufficient for the formation of memories (). , p. 102; ; ). Even today, only about half of teachers and the general public, depending on the country, agree that "learning occurs through the modification of the brain's neural connections" (

If anyone should appreciate that teaching and learning are biological phenomena, one would predict it would be biologists, and scientists more generally. However, few of us were likely taught about the neurobiology of learning in our pedagogical training. In this paper, we will first explore how one might conceptualize learning as a biological process in the context of a common teaching technique called the think-pair-share. Then, we will give an overview of what is known from biological research about the neurobiological basis of learning and explore how various teaching techniques might harness known neurological mechanisms to promote the creation and retrieval of long-term memories. This Feature does not aspire to give instructions for how one should teach. Certainly, there have been many attempts to use the findings of neuroscience to create guidelines for instruction, particularly in K-12 education, and even to sell "brain-based curricula," but given the complexity of human learning, many neuroscientists believe these attempts have been at best premature and, at worst, "distortions" of the science ( Bruer, 2006 Goswami, 2006 2007 Howard-Jones, 2014 ). Instead, we aspire to connect what is known in neurobiology to what is known from science education research about how innovative teaching is effective at promoting learning (). ; ; James S. McDonnell Foundation, ;

A NEUROBIOLOGICAL CONCEPTUALIZATION OF THE THINK-PAIR-SHARE

Each of our students arrives in class with a human brain, which on average has 86 billion neurons arranged in hundreds of brain regions, each with different functions (). These neurons connect with one another to form neural circuits, making an estimated 100 trillion contacts with one another, called synapses ( Williams and Herrup, 1988 ). Although there is much that we do not understand about how the brain functions, we do know that brains are always active, always analyzing and responding to a myriad of internal and external cues, both consciously and subconsciously. As an example, if we could look inside student brains as they are learning through participating in a common nonlecture classroom activity, the think-pair-share, what might we see?

Imagine a class full of students. In a think-pair-share, they all think individually about a solution to a problem, pair with a neighbor to discuss their ideas, and share their thoughts with a larger group ( Lyman, 1981 Tanner, 2009b ). Although this technique is relatively easy to implement, its apparent simplicity belies the deeper intricacies of the tasks the students' brains must do to accomplish it. During the think phase, to be most effective, the students' task must pique their interest and motivate them to pay attention to the concept under study. That attention might cause the release of chemicals in the brain, such as particular types of Everitt and Robbins, 1997 Schultz and Dickinson, 2000 Lupien and McEwen, 1997 ; ). ). The task may also tie the concept to other topics from the class or from real life, challenging the students and the brain cells within them to form the associations that can aid long-term memory formation and retrieval. In the next phases, the pair and the share, the students discuss the task with peers, practicing the skills and habits of thought necessary to master the subject. During this phase, the students have the confidence to complete this activity with a community of supportive peers. These feelings of confidence and community may also promote learning indirectly by preventing the release of chemicals in the brain and body, such as stress hormones, that could inhibit learning ( ; ; neurotransmitters, which carry signals between synapses, that promote learning (

Thus, all of the phases of the think-pair-share are in service to the ultimate goal, encoding memory in synaptic connections and neural circuits. Hopefully, the think-pair-share has caused the connections between nerve cells inside the students' brains to be changed for a long time, allowing them to recall the solution to the task months later and perhaps for the rest of their lives. So, how exactly do neurons and synapses change when a memory is created and retrieved? Below, we delve into the neurobiology of learning on a more detailed level to illuminate the changes that may be occurring in students' brains as they learn.

HOW DO TWO NEURONS COMMUNICATE WITH EACH OTHER?

The consensus among neuroscientists is that the basis of learning and memory creation lies in changes in electrically active nerve cells, called neurons, and the connections between them, the synapses. Although neurons come in many diverse shapes, a stereotypical example of two neurons is shown in . Neurons have many thin projections extending from the cell body, called dendrites and axons (). In general, dendrites receive signals from the outside world or from other neurons, and axons send signals to other neurons or to muscles or glands. When a neuron's dendrites are adequately stimulated, an electrical signal flows down the dendrites, through the cell body, and down the axon (). Colloquially, this process is referred to as firing.

At the synapse, this electrical signal is passed onto other neurons. However, most of the time, the signal cannot be passed on directly, because the end of an axon is usually very close to part of another neuron's dendrite but is not directly continuous with it (). Therefore, to propagate the signal, the sending neuron, the presynaptic neuron, must convert the electrical signal to a chemical signal before it can be sent to the receiving neuron, the postsynaptic neuron. In other words, in response to electrical stimulation, presynaptic neurons release neurotransmitters that carry the cellular signal across the synaptic gap. There are dozens of different types of neurotransmitters, each with different possible effects, and the neurotransmitter(s) released at a particular synapse depends on the identity of the presynaptic neuron. After release, the neurotransmitters diffuse across the synapse and bind to receptors on (or in) the postsynaptic cell (). When a neurotransmitter binds to a receptor, it directly or indirectly creates or modulates an electrical signal in the postsynaptic neuron, perhaps causing it to fire. A postsynaptic neuron might have tens of thousands of presynaptic neurons of different types synapsing onto it (). This system of using chemical neurotransmitters to send signals across synapses to alter the postsynaptic neuron's behavior allows for the postsynaptic neuron to integrate all the signals it receives and produce sensible behavioral responses to complex environmental stimuli.

HOW DOES THE BRAIN CHANGE THROUGH SYNAPTIC PLASTICITY? NEURONS THAT FIRE TOGETHER, WIRE TOGETHER

While the basic architecture of the human brain is set up early in childhood, learning and memory is possible because individual neurons retain the ability to change their signaling and synaptic connections throughout a person's life. Brain changes have been observed in neurons and synapses both after extreme changes in sensory experiences, like blindness, and after more subtle ones, like navigating a maze for the first time ( Wiesel and Hubel, 1963 Karlsson and Frank, 2008 ). For the most part, brain changes do not seem to arise from the birth of new neurons, called ; neurogenesis. While neurogenesis does occur in the adult human brain, it only does so in certain brain areas, and newly born neurons represent only ∼0.004% of the of the total population of neurons at any given time (; ; ).

Instead, learning appears to occur primarily because of changes in the strength and number of the connections between existing neurons, a process called synaptic plasticity. For the most part, the changes occur in such a way that frequently used connections between neurons are enhanced the most. If the activation of a presynaptic neuron causes a postsynaptic neuron to fire, the neurons will alter themselves molecularly and cellularly so that the presynaptic neuron becomes even better at triggering the firing of the postsynaptic neuron ( Hebb, 1949 Holtmaat and Svoboda, 2009 Shatz, 1992 ). ; ). If the coactivation of two neurons happens repeatedly, these new synapses can last for long periods of time, providing a neural substrate for long-term memory. The principle that that coactivation of two neurons leads to a stronger connection between those neurons was pithily summarized in the early 1990s by neuroscientist Carla Shatz as, "Neurons that fire together, wire together" ( ; ). For example, in the short term, more neurotransmitter receptors may be inserted into the membrane of the synapse of the postsynaptic neuron, making it more receptive to the presynaptic neuron's signals, and in the long term, new synapses between the two neurons may grow (

HOW DOES SYNAPTIC PLASTICITY RELATE TO LEARNING AND MEMORY?

Researchers have repeatedly shown that neural connections in many different parts of the brain can change and that this synaptic plasticity is associated with and leads to behavioral learning and the formation of memories. For instance, neuroscientists found that training mice in a novel motor task induced an outgrowth of new synapses very quickly, within an hour, in the motor cortex, a part of the brain dedicated to planned movements. Furthermore, they found that further training stabilized some of the new synapses so that they remained present for weeks, months, and possibly years (; ). We also know that blocking specific processes and molecules important for synaptic plasticity, such as particular neurotransmitter receptors, prevents behavioral learning, giving a causal connection between synaptic plasticity and learning (). These are just some of the thousands of studies in all sorts of animal models that link synaptic plasticity between neurons to the changes in behavior that indicate learning and memory formation ().

WHAT CAN AFFECT THE ABILITY OF NEURAL CONNECTIONS TO CHANGE?

Although nearly all neural connections have the ability to exhibit plasticity, there are multiple factors that can either promote or inhibit neural change. Some of the same processes that alter one's ability to learn are also associated with neurochemicals that affect synaptic plasticity. For example, we all know that it is easier to learn something if we are paying attention and motivated by the material. Scientists have identified a set of neurotransmitters that are commonly released in contexts involving motivation and attention. Broadly speaking, the neurotransmitter dopamine is associated with reward or the anticipation of reward, while the neurotransmitter acetylcholine (ACh) is released during situations of novelty or surprise ( Everitt and Robbins, 1997 Schultz and Dickinson, 2000 ). Unsurprisingly, blocking either neurotransmitter impairs synaptic plasticity, while the presence of either neurotransmitter enhances it (; ; ; ). On the basis of these laboratory studies, neuroscientists would predict that when our students are motivated and attentive in our class, their brains are releasing dopamine and ACh, priming them for plasticity and learning. ;

On the flip side, there are other factors that can inhibit plasticity. Everyone has felt how a stressful or scary event causes heart rates and blood pressures to rise. It turns out that some of the same chemicals that are involved in the body's response to fear and stress also pass into the brain and can profoundly affect processes there. One chemical in particular, the stress hormone cortisol, seems to be particularly relevant to plasticity and learning. The brain is rich in receptors for cortisol, especially in areas relevant to memory (). While mild elevations in cortisol can boost performance on memory tests, high levels inhibit both the encoding and the retrieval of memory in both animals and humans ( Lupien and McEwen, 1997 Conrad, 2010 ). Fortunately, those same studies have shown that this shrinkage is reversible. On the basis of these studies, neuroscientists would likely predict that high levels of stress in students in classrooms would be an impediment to learning, and removing some stressors could facilitate it. ; ). Synaptic plasticity follows the same pattern, wherein high levels of cortisol disrupt the strengthening of connections between synapses (). The negative effects of high levels of stress and cortisol on memory compound over time. Many different studies using all sorts of stressors have found that chronic stress can impair learning and memory and is even associated with the shrinkage of certain brain structures in humans (

HOW ARE MEMORIES STORED AND RETRIEVED?

For learning to be useful and affect behavior, once the learning is complete and synaptic connections are strengthened, memories must be stored and then retrieved when needed. While much is still to be discovered, neuroscientists propose that memories are stored in groups of neurons that all become strongly connected to each other during learning and synaptic plasticity. Just as learning to perform a certain protocol in a biology lab course, for example, might tie together many different types of information, such as remembering the quantities of chemicals used, the motions for combining them, and the look of the product once the protocol is completed, the neuronal memory ensemble may include neurons that are physically located in many different places in the brain that nevertheless are synaptically connected and that increase the strength of their connections to each other during learning (). Memories are retrieved through reactivation of the neurons whose synapses were altered in the initial creation of a memory, particularly in the time shortly after that memory was created (; ; Goshen, 2014 ). In fact, recent technological advances have allowed us to reactivate certain memories and induce particular learned behaviors on demand in mice through artificial stimulation of the specific neurons that were active during the formation of those memories ().

However, just because the neurons involved are scattered throughout the brain does not mean that synapses are altered at random whenever something new is learned. On the contrary, the plasticity that occurs after learning is specific to the particular neurons that will go on to form the memory ensemble. Scientists have found that of the tens of thousands of synapses a postsynaptic neuron may have, for the most part, only the synapses connected to a particular presynaptic neuron will be strengthened when it is fired strongly by that presynaptic neuron (). The specificity of synaptic plasticity may mean that learning one fact or skill may not easily or immediately translate into learning another fact or skill, even if the two facts or skills seem closely related.

In summary, then, the brain creates memories through altering the synaptic connections between specific neurons, stores them in connected ensembles of neurons, and retrieves them by reactivating those same neurons and connections. Importantly, the ability of the synapses to respond to learning experiences by undergoing synaptic plasticity is modulated by the presence of other chemical factors, such as dopamine, ACh, and cortisol, which are associated with particular emotional, environmental, and cognitive states. Some of these chemicals, such as the neurotransmitters dopamine and ACh, are associated with attention and motivation, positively influence synaptic plasticity and learning, while other compounds associated with stress, like the hormone cortisol, negatively influence synaptic plasticity and learning. So, how can we use this information about how the brain creates and retrieves memories to understand how various teaching techniques may affect our students' brains?

HOW COMMON TEACHING TECHNIQUES MAY AFFECT THE NEUROBIOLOGY OF LEARNERS' BRAINS

We will discuss here several different techniques that fall under the umbrella of "scientific teaching" and how they may affect the neurobiology of learning. We will do this by introducing four different hypothetical students-Alessa, Joe, Morgan, and Elijah-and their experiences in a traditionally taught first-year introductory biology class that lacks these techniques. The four techniques that we will focus on are frequent homework, concept maps, problem-based learning, and culturally diverse examples, although we will also briefly discuss other techniques that may take advantage of similar neural processes as these four (). For each technique, we will first present the student's experience in context, then show evidence from science education and psychology research for why the technique might address the student's difficulties, and finally discuss the likely neurobiological basis for why the technique may be effective.

TABLE 1.

Neuroscientific principle discussed in this Feature

Psychological or educational findings or ideas that may correspond to the neuroscientific principle

Teaching techniques that may harness the corresponding principlea

Synaptic plasticity is specific to the particular neurons that are active together.

Active forms of studying improve test performance over passive forms.
Frequent, active homework

Memories are encoded as synaptic networks.

Encoding knowledge relationally helps in remembering it.
Concept maps

Dopamine and ACh, released during states of motivation and attention, boost synaptic plasticity.

Motivation and attention increase learning.
Problem-based learning

Cortisol, released during stress, depresses synaptic plasticity.

Stereotype threat undermines learning and performance.
Using culturally diverse examples

NEUROBIOLOGICAL REANALYSIS OF THE THINK-PAIR-SHARE

Now knowing some ways that active learning can affect the brain, let us reanalyze the "simple" think-pair-share and see how the neural processes outlined earlier can come together to promote learning. In a think-pair-share, the questions posed to the students are usually interesting and motivating to provide a rich basis for thought and discussion. By gaining the students' interest and attention, we may be promoting release of neurotransmitters such as dopamine and ACh that enhance neural plasticity. Such questions may also prompt students to connect the material under study to previously learned information or real-world issues, possibly encouraging the formation of neural networks that can promote retrieval of the material in the future. In addition, as students are writing about and discussing the questions with their peers, they are practicing the problem-solving and thinking skills necessary for gaining expertise in a subject. In other words, they may be engaging not only the parts of their brain responsible for reciting semantic information but also those important in developing skills and habits. Finally, it is important to note what is not going on during a think-pair-share. Think-pair-shares are low-stakes and involve the participation of the entire class. The friendly and communal atmosphere that regular think-pair-shares promote may increase belonging and decrease stress, potentially reducing the amount of cortisol released in student brains and removing a factor that can impede neural plasticity and learning.

WHAT MIGHT TEACHING AND LEARNING LOOK LIKE AS NEUROSCIENCE ADVANCES?

Teaching and learning are fundamentally neurobiological phenomena. However, while neurobiologists have figured out the basics behind how the brain creates and stores memories, there is still much more to discover. For example, there is currently very little neurobiology research that might explain how concepts as important to learning as metacognition and knowledge organization might be expressed in the brain. Future advances in neuroscience will almost certainly allow us to more easily investigate how complex phenomena like these are represented in the brain and how they affect synaptic plasticity. In addition, currently, a significant portion of our knowledge linking learning to cellular and molecular changes in the brain is indirect, deriving from animal studies or studies conducted in the confinement of a magnetic resonance imaging scanner. In the future, we may be able to look into the human brain in real time and get more direct information about how synapses and circuits change in students as they learn.

Because teaching and learning arise from properties of the human brain, the ability of a teaching technique to harness the processes in a student's brain that support the formation and retrieval of long-term memories will help determine that technique's effectiveness in promoting that student's learning. As we learn more about the brain, we will increasingly be able to use the results of neurobiological studies to more effectively select and develop new pedagogical techniques. Translating the results of neuroscience to the classroom will help future instructors truly teach their students from the inside out.

Acknowledgments

We thank Dr. Robin Wright for her early inspiration and conversations about this Feature. We also thank Natalia Caporale, Sara Brownell, Colin Harrison, Sarah Bissonnette, Kristin de Nesnera, Rhea Kimpo, and Henry Mahncke for helpful ideas and discussion.

REFERENCES

Hartley D. Observations on Man, His Frame, His Duty, and His Expectations. vol. 2. Bath and London: Samuel Richardson; 1749. [Google Scholar]

Hebb DO. The Organization of Behavior: A Neuropsychological Theory. New York: Wiley; 1949. [Google Scholar]

Howard-Jones PA, Franey L, Mashmoushi R, Liao Y-C. The neuroscience literacy of trainee teachers. 2009. British Educational Research Association Annual Conference, held September 2-5, 2009, in Manchester, England.

James S. McDonnell Foundation. The Santiago Declaration. 2007. www.jsmf.org/santiagodeclaration/ (accessed 24 September 2015)

Lyman F. The responsive classroom discussion: the inclusion of all students. In: Anderson A, editor. In: Mainstreaming Digest. College Park: University of Maryland; 1981. pp. 109-113. [Google Scholar]

Morris RG, Anderson E, Lynch GS, Baudry M. Selective impairment of learning and blockade of long-term potentiation by an N-methyl-d-aspartate receptor antagonist, AP5. Nature. 1986;319:774-776. [[PubMed] Google Scholar]

# data[].attributes.attachment_link.title
Teaching as Brain Changing: Exploring Connections between Neuroscience and Innovative Teaching

# data[].attributes.attachment_link.description
One would hope that of the many ways to conceptualize teaching and learning, scientists would view these processes as driving biological changes in the brain. Here, the authors draw connections between innovative teaching techniques and neuroscience that may support our understanding of why innovative teaching is so effective at promoting learning.

# data[].attributes.body
https://www.verywellmind.com/what-is-a-neurotransmitter-2795394

# data[].attributes.attachment_link.readable_text
A neurotransmitter is a chemical messenger that carries, boosts, and balances signals between neurons (also known as nerve cells) and target cells throughout the body. These target cells may be in glands, muscles, or other neurons.

Billions of neurotransmitter molecules work constantly to keep our brains functioning, managing everything from our breathing to our heartbeat to our learning and concentration levels. They can also affect a variety of psychological functions such as fear, mood, pleasure, and joy.

How Neurotransmitters Work

In order for neurons to send messages throughout the body, they need to be able to communicate with one another to transmit signals. However, neurons are not simply connected to one another. At the end of each neuron is a tiny gap called a synapse and in order to communicate with the next cell, the signal needs to be able to cross this small space. This occurs through a process known as neurotransmission.

In most cases, a neurotransmitter is released from what's known as the axon terminal after an action potential has reached the synapse, a place where neurons can transmit signals to each other.

When an electrical signal reaches the end of a neuron, it triggers the release of small sacs called vesicles that contain the neurotransmitters. These sacs spill their contents into the synapse, where the neurotransmitters then move across the gap toward the neighboring cells. These cells contain receptors where the neurotransmitters can bind and trigger changes in the cells.

After release, the neurotransmitter crosses the synaptic gap and attaches to the receptor site on the other neuron, either exciting or inhibiting the receiving neuron depending on what the neurotransmitter is.

Sometimes neurotransmitters can bind to receptors and cause an electrical signal to be transmitted down the cell (excitatory). In other cases, the neurotransmitter can actually block the signal from continuing, preventing the message from being carried on (inhibitory).

Inactivation of Neurotransmitters

So what happens to a neurotransmitter after its job is complete? Once the neurotransmitter has had the designed effect, its activity can be stopped by three mechanisms:

Degradation: An enzyme changes the structure of the neurotransmitter so it can't be recognized by the receptor

Diffusion: The neurotransmitter drifts away from the receptor

Reuptake: The whole neurotransmitter molecule is taken back up by the axon of the neuron that released it

The actual identification of neurotransmitters can actually be quite difficult. While scientists can observe the vesicles containing neurotransmitters, figuring out what chemicals are stored in the vesicles is not quite so simple.

Because of this, neuroscientists have developed a number of guidelines for determining whether or not a chemical should be defined as a neurotransmitter:﻿﻿

Presence of the chemical within the cell. The chemical is either synthesized in the neuron or otherwise found in it.

Stimulus-dependent release. It is released in appropriate quantities by the neuron upon stimulation.

Action on postsynaptic cell. The chemical must be released by the presynaptic neuron, and the postsynaptic neuron must contain receptors that the chemical will bind to.

Mechanism for removal. A specific mechanism exists to remove the chemical from its site of activation after its work is done.

Classification

Neurotransmitters play a major role in everyday life and functioning. Scientists do not yet know exactly how many neurotransmitters exist, but more than 60 distinct chemical messengers have been identified.﻿﻿

Neurotransmitters can be classified by their function:﻿﻿

Excitatory neurotransmitters: These types of neurotransmitters have excitatory effects on the neuron, meaning they increase the likelihood that the neuron will fire an action potential. Some of the major excitatory neurotransmitters include epinephrine and norepinephrine.

Inhibitory neurotransmitters: These types of neurotransmitters have inhibitory effects on the neuron; they decrease the likelihood that the neuron will fire an action potential. Some of the major inhibitory neurotransmitters include serotonin and gamma-aminobutyric acid (GABA).

Modulatory neurotransmitters: These neurotransmitters, often referred to as neuromodulators, are capable of affecting a larger number of neurons at the same time. These neuromodulators also influence the effects of other chemical messengers. Where synaptic neurotransmitters are released by axon terminals to have a fast-acting impact on other receptor neurons, neuromodulators diffuse across a larger area and are more slow-acting.

There are a number of different ways to classify and categorize neurotransmitters. In some instances, they are simply divided into monoamines, amino acids, and peptides.﻿﻿

Neurotransmitters can also be categorized into one of six types:

Amino Acids

Gamma-aminobutyric acid (GABA): This naturally occurring amino acid acts as the body's main inhibitory chemical messenger. GABA contributes to vision, motor control, and plays a role in the regulation of anxiety. Benzodiazepines, which are used to help treat anxiety, function by increasing the efficiency of GABA neurotransmitters, which can increase feelings of relaxation and calm.

Glutamate: The most plentiful neurotransmitter found in the nervous system, glutamate plays a role in cognitive functions such as memory and learning. Excessive amounts of glutamate can cause excitotoxicity resulting in cellular death. This excitotoxicity caused by glutamate build-up is associated with some diseases and brain injuries including Alzheimer's disease﻿﻿ , stroke, and epileptic seizures.

Oxytocin: This powerful hormone acts as a neurotransmitter in the brain. It is produced by the hypothalamus and plays a role in social recognition, bonding, and sexual reproduction.﻿﻿ Synthetic oxytocin such as Pitocin is often used as an aid in labor and delivery. Both oxytocin and Pitocin cause the uterus to contract during labor.

Endorphins: These neurotransmitters than inhibit the transmission of pain signals and promote feelings of euphoria. These chemical messengers are produced naturally by the body in response to pain, but they can also be triggered by other activities such as aerobic exercise.﻿﻿ For example, experiencing a "runner's high" is an example of pleasurable feelings generated by the production of endorphins.

Monoamines

Epinephrine: Also known as adrenaline, epinephrine is considered both a hormone and a neurotransmitter. Generally, epinephrine is a stress hormone that is released by the adrenal system. However, it functions as a neurotransmitter in the brain.﻿﻿

Norepinephrine:This naturally occurring chemical is a neurotransmitter that plays an important role in alertness is involved in the body's fight or flight response. Its role is to help mobilize the body and brain to take action in times of danger or stress. Levels of this neurotransmitter are typically lowest during sleep and highest during times of stress.

Histamine: This organic compound acts as a neurotransmitter in the brain and spinal cord.﻿﻿ It plays a role in allergic reactions and is produced as part of the immune system's response to pathogens.

Dopamine: Commonly known as the feel-good neurotransmitter, dopamine is involved in reward, motivation, and additions.﻿﻿ Several types of addictive drugs increase dopamine levels in the brain. This chemical messenger also plays an important role in the coordination of body movements. Parkinson's disease, which is a degenerative disease that results in tremors and motor movement impairments, is caused by the loss of dopamine-generating neurons in the brain.

Serotonin: A hormone and neurotransmitter, serotonin plays an important role in regulating and modulating mood, sleep, anxiety, sexuality, and appetite. Selective serotonin reuptake inhibitors (SSRIs) are a type of antidepressant medication commonly prescribed to treat depression, anxiety, panic disorder, and panic attacks. SSRIs work to balance serotonin levels by blocking the reuptake of serotonin in the brain, which can help improve mood and reduce feelings of anxiety.﻿﻿

Adenosine: This naturally occurring chemicalacts as a neuromodulator in the brain and is involved in suppressing arousing and improving sleep.

Adenosine triphosphate (ATP): Considered to be the energy currency of life, ATP acts as a neurotransmitter in the central and peripheral nervous systems.﻿﻿ It plays a role in autonomic control, sensory transduction, and communication with glial cells. Research suggests it may also have a part in some neurological problems including pain, trauma, and neurodegenerative disorders.

Gasotransmitters

Nitric oxide: This compound plays a role in affecting smooth muscles, relaxing them to allow blood vessels to dilate and increase blood flow to certain areas of the body.

Carbon monoxide: This colorless, odorless gas can have toxic and potentially fatal effects when people are exposed to high levels of the substance. However, it is also produced naturally by the body where it acts as a neurotransmitter that helps modulate the body's inflammatory response.﻿﻿

Acetylcholine

Acetylcholine: This is the only neurotransmitter in its class. Found in both the central and peripheral nervous systems, it is the primary neurotransmitter associated with motor neurons.﻿﻿ It plays a role in muscle movements as well as memory and learning.

When Neurotransmitters Do Not Work Right

As with many of the body's processes, things can sometimes go awry. It is perhaps not surprising that a system as vast and complex as the human nervous system would be susceptible to problems.

A few of the things that might go wrong include:

Neurons might not manufacture enough of a particular neurotransmitter

Neurotransmitters may be reabsorbed too quickly

Too many neurotransmitters may be deactivated by enzymes

Too much of a particular neurotransmitter may be released

When neurotransmitters are affected by disease or drugs, there can be a number of different adverse effects on the body. Diseases such as Alzheimer's, epilepsy, and Parkinson's are associated with deficits in certain neurotransmitters.

Health professionals recognize the role that neurotransmitters can play in mental health conditions, which is why medications that influence the actions of the body's chemical messengers are often prescribed to help treat a variety of psychiatric conditions.

For example, dopamine is associated with such things as addiction and schizophrenia. Serotonin plays a role in mood disorders including depression and OCD.﻿﻿ Drugs, such as SSRIs, may be prescribed by physicians and psychiatrists to help treat symptoms of depression or anxiety.

Drugs That Influence Neurotransmitters

Perhaps the greatest practical application for the discovery and detailed understanding of how neurotransmitters function has been the development of drugs that impact chemical transmission. These drugs are capable of changing the effects of neurotransmitters, which can alleviate the symptoms of some diseases.

Agonists vs Antagonists: Some drugs are known as agonists and function by increasing the effects of specific neurotransmitters. Other drugs and referred to as antagonists and act to block the effects of neurotransmission.﻿﻿

Direct vs Indirect Effects:These neuro-acting drugs can be further broken down based on whether they have a direct or indirect effect. Those that have a direct effect work by mimicking the neurotransmitters because they are very similar in chemical structure. Those that have an indirect impact work by acting on the synaptic receptors.

Drugs that can influence neurotransmission include medications used to treat illness including depression and anxiety, such as SSRIs, tricyclic antidepressants, and benzodiazepines.

Illicit drugs such as heroin, cocaine, and marijuana also have an effect on neurotransmission. Heroin acts as a direct-acting agonist, mimicking the brain's natural opioids enough to stimulate their associated receptors. Cocaine is an example of an indirect-acting drug that influences the transmission of dopamine.﻿﻿

A Word From Verywell

Neurotransmitters play a critical role in neural communication, influencing everything from involuntary movements to learning to mood. This system is both complex and highly interconnected. Neurotransmitters act in specific ways, but they can also be affected by diseases, drugs, or even the actions of other chemical messengers.

# data[].attributes.attachment_link.title
How Neurotransmitters Work and What They Do

# data[].attributes.attachment_link.description
A neurotransmitter is a chemical messenger that carries, boosts, and balances signals between neurons (also known as nerve cells) and target cells throughout the body. These target cells may be in glands, muscles, or other neurons. Billions of neurotransmitter molecules work constantly to keep our brains functioning, managing everything from our breathing to our heartbeat to our learning and concentration levels.

# data[].attributes.body
https://www.researchgate.net/publication/329773687_INFLUENCE_OF_NEUROTRANSMITTERS_ON_MEMORY_AND_LEARNING
Anastasios (Tassos) Bletsas

# data[].attributes.body
The human brain contains an estimated 86 billion neurons. Those billions of brain cells communicate by passing chemical messages at the synapse, the small gap between cells, in a process called neurotransmission. Those chemical messages are unique molecules called neurotransmitters. There are many types of neurotransmitters in the brain, but they do have a few things in common. Neurotransmitters are endogenous—or produced inside the neuron itself. When a cell is activated, these neurochemicals are released into the synapse from specialized pouches clustered near the cell membrane called synaptic vesicles. Specific receptors on neighboring cells can then take up the neurotransmitters, which can increase or decrease the signal being passed along a particular circuit.

# data[].attributes.body
The infinite potential of our brain: a fascinating topic through which to understand the possibility of improving our daily life.

# data[].attributes.attachment_link.readable_text
Abstract

Meditation and Yoga techniques are receiving increased attention throughout the world, due to the accumulation of evidence based research that proves the direct and indirect benefits of such practices. Based on studies conducted so far, it has been found that the practice of meditation triggers neurotransmitters that modulate psychological disorders such as anxiety. This paper will review the psychological effects of the practice of meditation, the role of neurotransmitters, and studies using EEG and fMRI.

Keywords: Meditation, Yoga, Neurotransmitters, brain mechanisms, Behaviour and Anxiety

Introduction

The art of meditation, which was once considered to be exclusively an Eastern practice, often associated with religion and spiritualism, has become a more scientific modality in recent years, and is accepted for routine practice in many parts of the world. No wonder Yoga Day is celebrated on 21 st June all over the world. Due to the observed direct and indirect benefits of Yoga practices, controlled research has been carried out on the physiological and neuropsychological aspects of various meditation techniques. Studies comparing other forms of psychotherapy, along with meditation therapy have also become part of the global research agenda.

There are various forms of meditation that have been designed and established by several sage-scientists of India since the time of Patanjali, who is known as the Father of Yoga according to regional Indian sources. Though there are many types of meditation practices, some of the well-known practices in the West are "Mindful Meditation", "Transcendental Meditation" and "Kundalini Meditation". More than 60% of the Indian population directly or indirectly, practice some kind of meditation as part of their traditional culture. In India, schools offer courses in Yoga and Meditation. For instance, the Vethathiri Maharishi Institute for Spiritual and Institutional Education (VISION) in India has created a complete curriculum for Yoga staring from kindergarten and going all the way to Ph.D level.

The Indian government has recently allocated a Ministry with a budget exclusively to fund research in Yoga and Ayurveda. Recently, the benefits of Yoga have been well-recognized in the west. Harvard, MIT and Yale universities have encouraged research on such a new modality. The NIH has allocated a budget for this research as part of the National Center for Complementary and Alternative Medicine (NCCAM). Many of these meditation techniques are used for different specific applications, and studies have shown that they have varying neurophysiological effects. The most common application of meditation is to alleviate stress and anxiety; therefore meditation is often considered as a form of relaxation therapy, more than as an alternative to traditional drug-based medicine.

Stress and Anxiety Disorders

Stress is a factor that has been shown to predispose chronic sufferers to develop many diseases including heart attack, cancer, infections and other neurological disorders. Meditation has proven to be a very good solution for stress management. Research conducted at the Maharishi Mahesh Yogi Institute for Management and Technology in the US has produced strong evidence of the direct benefits of meditation on stress management. Stress is also largely responsible for anxiety disorders. Anxiety disorders affect approximately 40 million adults in the United States, ages 18 and older, in a given year [ 1]. It is alarming that a large national survey found 8% of teens (13 to 18 years) have some form of anxiety disorder. There are several types of anxiety disorder. Apart from Generalized Anxiety Disorder (GAD), when one worries excessively, Obsessive-Compulsive Disorder (OCD) is another type of anxiety disorder in which affected individuals display uncontrollable, intrusive thoughts, obsessions and compulsions in an attempt to reduce the anxiety. Post-Traumatic Stress Disorder (PTSD) is when the victims who have been directly or indirectly affected by a traumatic event, suffer distress and either display avoidance symptoms, re-experiencing symptoms, or hyperarousal symptoms [ 2]. Social anxiety is not only the fear of having to be in front of people, but is also the fear of engaging in social activities because the sufferer is anxious of being judged [ 3]. And lastly, anxiety also stems from phobias-an intense fear of a certain specific stimulus.

This article will review the neurobiological changes produced by meditation, and its applicability to anxiety will be covered.

Neurotransmitters

Neurotransmitters play a key role in modulating and regulating behavior and anxiety. Studies have demonstrated a negative correlation between gamma-aminobutyric acid (GABA) activity and anxiety. Although GABA receptors can be found throughout the brain, research has indicated particularly decreased GABA activity in the hippocampus, lingual gyrus, middle temporal gyrus, visual cortex [ 4], orbital cortex and insula [ 5] in patients with panic disorder when compared to controls. GABA knockout mice (or in other words, mice that have been engineered to have dysfunction of GABA receptors) exhibited fear related behaviors, such as heightened sensitivity to natural aversive stimuli, increased ability to recall negative associations and augmented harm avoidance behavior [ 6]. Moreover, a patient with severe GAD was found to have a genetic mutation in a GABA receptor subunit; this mutation lessened the binding capacity of substrate to the GABA receptors [ 7]. These studies prove that lower levels of GABA or GABA receptors are associated with higher levels of anxiety.

Positron emission tomography (PET) was used to compare the regional cerebral blood flow (rCBF) of eight Tibetan Buddhist meditators. As they performed complex cognitive tasks, it was found that the meditators had significantly higher rCBF in the prefrontal cortex (PFC) than the controls. The PFC is a brain region that is largely responsible for executive functions such as decision making and problem solving ability [ 8]. When the prefrontal cortex is stimulated, it activates the reticular nucleus of the thalamus (RE), which in turn produces GABA [ 9, 10]. Meditators also have a higher threshold concentration and alertness, which are cognitive functions controlled by the PFC. Therefore, an increase in the PFC region upon meditation is correlated to an increase in GABA production since the RE will be excited [ 11]. It has also been hypothesized that transcendental meditation increases GABA-inergic tone [ 12]. By increasing GABA levels, meditation may help to decrease anxiety levels.

Serotonin, a powerful neurotransmitter, plays a major role in mood regulation. A deficiency of serotonin is associated with depression, and a study revealed that serotonin knockout mice, with the deletion of a serotonin receptor, IA, exhibited more fear. Another experiment, which compared the serotonin levels of healthy controls with those of patients diagnosed with panic disorder using a PET scan, found out that the patients had about one-third lower level of serotonin 1A receptors in regions such as the anterior cingulate, posterior cingulate and midbrain raphe [ 13]. It is remarkable that several studies performed on participants after they concluded their meditation sessions, observed a rise in the breakdown products of serotonin in the urine [ 8, 14]. In one such study of Transcendental Meditation practitioners, the urine samples were analyzed for serotonin, and the meditators exhibited a higher level before meditation when compared to the controls, and a much higher level after meditation [ 15].

Norepinephrine (NE) is another neurotransmitter involved in anxiety. The brain region called locus coeruleus is hypothesized to contain the greatest concentration of NE in the brain, and an increase of activity in this region together with increased NE has been identified in individuals with anxiety. In an experiment, when NE release was decreased in rats, the rats were not able to respond normally to fear inducing stimuli [ 16]. These findings suggest that a lower level of NE indicates lesser anxiety, and this has been confirmed in meditators. In a study which compared NE levels between two groups of heart failure patients-one which practiced meditation and another which attended weekly meetings, it was determined that the group practicing meditation displayed lower levels of NE in their blood samples compared to the controls [ 17]. In another experiment, regular meditators utilizing either TM or Sidhi-TM techniques expressed lower NE levels than the control group of healthy subjects, when their plasma catecholamine levels were measured in mornings and evenings [ 18].

A neurotransmitter that is commonly associated with reward-motivated behavior and social anxiety is dopamine. A research experiment found out that people with generalized social phobia tended to have lower dopamine levels than healthy subjects [ 19]. Another study that incorporated PET scans observed an increase in dopamine levels in the ventral striatum of participants during practice of Yoga Nidra meditation [ 8, 20]. There is also some evidence that when melatonin, a hormone generally known to aid sleep, was injected in rats, the rats showed less anxiety and spent longer time in a plus-maze [ 21]. Moreover, a review cited nine different studies that concluded that lower levels of anxiety could be produced when melatonin was given as a medication versus placebo [ 22]. In a within-subject study, plasma melatonin levels were obtained from a group of TM-Sidhi meditators when they meditated on two different nights-one night they meditated for about an hour, and another night, they sat quietly instead for the same one hour. The research study discovered that the melatonin levels, which were approximately the same pre-meditation, were higher in the nights they meditated than in the control nights [ 23].

Brain Electroencephalographic Measurements

Alpha waves are generally associated with more relaxed and alert states of mind, and an experiment conducted noticed that individuals clinically diagnosed to have anxiety disorder displayed lower activity of alpha waves, while individuals who were only prone to have anxiety had slightly higher alpha activity, and non-anxiety prone normal subjects exhibited the highest alpha activity; therefore, the number of oscillations in the alpha band increased as the levels of anxiety decreased [ 24]. Furthermore, a biofeedback study that enabled subjects to control their alpha activity found that when individuals with higher anxiety traits increased their alpha wave activity, they displayed a reduction of anxiety symptoms [ 25]. Research studies comparing alpha wave activity in meditators and control subjects concluded that people who meditate display higher alpha activity than the controls [ 26].

Theta oscillations assist with alertness and the ability to process information quickly [ 26]. Frontal midline theta waves which can be stimulated during mental tasks as well as in nocturnal sleep have also been found to play a key role in personality traits. A research study showed that higher theta wave activity was identified in individuals with the lowest anxiety scores, the highest extrovert scores and the lowest scores on a neurotic scale [ 26, 27]. Therefore, an increase in the theta levels can decrease anxiety levels. Research studies have also reported an increase in the theta activity in meditators, and four studies mentioned an increase in the frontal midline theta power during meditation [ 26]. Individuals who have practiced meditation for a much longer time displayed higher theta and alpha power than non-meditators [ 26, 28]. While studies have predominantly found an overall increase in alpha waves in meditation, a few reports have found a decrease in alpha power. Studies conducted on theta waves have more consistently displayed an increase in meditation.

Mindfulness and Mantra

Mindfulness meditation is the conscious direction of attention to an object, person, idea or stimulus; this activity requires plenty of attention. Studies have proven that attention training programs have helped to lower anxiety levels, as the subjects are able to shift their attention away from the threatening stimulus [ 29]. In a research experiment, victims, who were sexually abused in their childhood, partook in an 8-week mindful meditation course, and they displayed statistically significant decreases in their PTSD symptoms, anxiety and depression [ 30]. When a group of PTSD survivors went through eight sessions of psychoeducation (education about mental health), and another group underwent mindful meditation, it was reported the latter group expressed a higher reduction in PTSD symptoms at the end [ 29, 31]. The efficacy of this meditation technique was analyzed in another study that performed a three year follow-up after a previous study in which 22 individuals diagnosed with anxiety partook in an 8 week long mindfulness based meditation program [ 32, 33]. Eighteen of these subjects participated in the follow-up study, and the data obtained demonstrated that the clinically and statistically significant reductions of the anxiety levels were still observed at the follow-up.

Another study conducted on subjects using fMRI concluded that there was higher connectivity in the least anxious patients [ 34]. A research study carried out on 26 patients with GAD compared the effectiveness of Mindfulness Based Stress Reduction (MBSR) and Stress Management Education (SME) using fMRI. The study found from the Blood Oxygen Level Dependent (BOLD) responses that meditation practice (MSBR) resulted in more connectivity between the amygdala and several regions of the PFC, amygdala and dorsolateral PFC when compared to SME. This was also consistent with the measured Beck Anxiety Inventory scores, where the meditators showed lower mean scores for anxiety symptoms than the SME participants [ 35]. This comparison is illustrated in :

Transcendental meditation (TM) using mantras is a technique where the participants silently repeat a word or phrase. Young adults in college were assigned to a TM program or wait-list control, and the TM group showed lower levels of anger, stress, depression and most importantly, anxiety after they were trained in TM [ 36]. additionally, two groups of war veterans with PTSD were studied; both received usual care, but one group went through mantra meditation. The meditators expressed higher reductions in PTSD symptoms and exhibited more improvement in their mental health, when compared to the control group [ 37].

When compared to a waiting-list control group and a group getting cognitive behavioral therapy (CBT), individuals performing Sahaja Yoga meditation proved to significantly reduce anxiety and depression [ 38]. Kundalini Yoga Meditation is the raising of body awareness by awakening the "chakras" or "kundalini energy" in the body, and there are several techniques; these techniques include meditation, breathing methods, yoga and mantras. An experiment conducted by Shannahoff-Khalsa et al revealed that a group of patients after 12 months of practicing Kundalini Yoga showed 55.6% improvement, and a reduction of 19.8 to 8.8 as a mean in the Yale-Brown Obsessive-Compulsive scale. In this research study, the technique comprised a combination of yoga postures and breathing techniques [ 39].

Conclusions

Our brains do not contain fixed hardwiring; the neural pathways and circuits can in fact change with learning and with mental exercises, and meditation may be a harmless way to encourage the growth of new neurons (neurogenesis) along with the formation of new connections between existing neurons (synaptogenesis). By tying together the neurobiological effects of neurotransmitters, brain waves, mental exercise and the empirical evidence from the psychological experiments, it is evident that meditation is an effective treatment for anxiety, and it does not suffer from any side effects. It may also function as a preventive medicine; therefore, it is highly recommended to everyone and not limited to patients suffering from disease. This review has only highlighted observations from the several studies already conducted. However, it is imperative to conduct many more studies on a larger scale to substantiate the reported effects of the overall meditation approach, and by probing into the different effects of the various meditation techniques to see if differences in technique make a difference to the outcomes.

​

Acknowledgement

Michael R Hamblin was supported by US NIH grant R01AI050875. Shanmugamurthy Lakshmanan would like to thank the World Community Service Center for the support.

Biographies

Divya Krishnakumar received her BS from UC San Diego in 2013, majoring in Cognitive Science and specializing in Neuroscience. With a fascination about the brain, she is particularly interested in researching about neurological disorders. Thus as an undergraduate student, she acquired research experience by working under the direction of distinguished neuroscientist Dr. V.S Ramachandran; she conducted research on individuals with OCD-like traits. Furthermore, she assisted with neurofeedback training on autistic children in Dr. Jaime Pineda's Cognitive Neuroscience laboratory. Her other passion is empowering young girls through a program called Full of Ourselves, which is a primary prevention program that emphasizes on increasing their overall mental and physical well-being.

Dr. Shanmugamurthy Lakshmanan is a Research Scientist at Wellman Center for Photomedicine, Harvard Medical School, Massachusetts. His research focus is on Nanotechnology and Siddha- Ayurveda Photomedicines. He is the Vice President for International Research for the World Institute for Scientific Exploration and a distinguished Scientific Advisor and Head of the Indian Division of Sciences. He is also the Editor-in-Chief of two peer reviewed international journals: 1) Ancient Science and 2) Ayurveda, that has been established by VRI Press, Vedic Research, Inc. USA.

References

# data[].attributes.attachment_link.title
Meditation and Yoga can Modulate Brain Mechanisms that affect Behavior and Anxiety-A Modern Scientific Perspective

# data[].attributes.attachment_link.description
Meditation and Yoga techniques are receiving increased attention throughout the world, due to the accumulation of evidence based research that proves the direct and indirect benefits of such practices. Based on studies conducted so far, it has been found ...

# data[].attributes.body
Neurotransmitters (NTs) guide our lives because they excite or inhibit neurons to varying degrees and at varying concentrations. The same neurotransmitter can activate a neuron when it is secreted in a certain part of the brain or inhibit its activity when it is produced in another part. Having a deficiency or an excess of some neurotransmitter can produce disorders on different levels.

# data[].attributes.headline
Hormones and Neurotransmitters: The Differences and Curious Similarities

# data[].attributes.subject
Hormones and Neurotransmitters: The Differences and Curious Similarities

# data[].attributes.body
Information found in https://medium.com/the-biochemists/hormones-and-neurotransmitters-the-differences-and-curious-similarities-46c6095b825

Neurotransmitters and hormones are two different types of chemicals that carry signals from one part of the body to another. Both chemicals play an important part in the body’s physiology. They control a variety of physical and psychological functions, including our mood, our eating patterns, our ability to learn, and our sleep cycles.

The Differences

Hormones and neurotransmitters are different chemical messengers, the former produced by the endocrine glands and the latter by the nervous system.

Hormones are usually secreted from the endocrine system and released into the bloodstream, but they act on distant target cells. Some hormones, like melatonin and cortisol, are actually produced in the brain, released in the blood, and affect other parts of the body.

On the other hand, neurotransmitters are released from the presynaptic nerve terminal in the brain. They move across the synaptic cleft, a small space between two adjacent neurons, and move to the next neuron (known as a postsynaptic neuron). There they bind to specific receptors, causing changes in the electrical properties of target cells, which can cause various postsynaptic effects. Neurotransmitters work locally and their actions are very fast.

Both hormones and neurotransmitters influence our thoughts and motivations, as well as our ability to learn and concentrate. However, neurotransmitters’ actions are short-lived while hormones act for longer periods of time. Furthermore, neurotransmitters can affect both voluntary actions (eating, bathing, walking) and involuntary actions (breathing, blinking). Hormones in the endocrine system always work involuntarily.

Curious Similarities

Research in the last couple of years has demonstrated that some hormones, work like neurotransmitters independently of their classical hormone actions. The most well-studied hormones are progesterone and estrogen, which are known as steroid hormones.

Steroid hormones are typically synthesized in the endocrine gland and bind to a receptor that then binds to a specific DNA sequence, affecting gene transcription. This process is a lengthy one, which means that steroid hormones work for a prolonged period of time.

However, Progesterone and estrogen are also synthesized in the neuronal circuit, specifically in the presynaptic terminal. They then bind to the membrane and intracellular receptors followed by neurotransmitter-like action, which is very fast and short-lived. These neurotransmitters-like steroids have multiple receptors. The steroid-receptor specific functions are not yet clearly understood.

Some well-studied neuroreceptors, like dopamine and serotonin are known to possess hormonal functions. Dopamine is a neurohormone released from the hypothalamus; its main function is to block the release of prolactin, another hormone, from the pituitary gland. As a neurotransmitter released from the central nervous system, it also has many functions including roles in cognition and motor activity.

Adrenaline and noradrenaline are two molecules that differ by one carbon atom. Adrenaline, which is produced by the adrenal gland, acts as a hormone. On the other hand, noradrenaline acts as a neurotransmitter in the central nervous system.

This is just a piece of a growing body of research suggesting that many hormones work as neurotransmitters and vice-versa. The next area of research here is to determine the receptor-specificity of these molecules to understand how their function may change depending on the receptor and mode of binding.

# data[].attributes.attachment_link.readable_text
A visualization of neurotransmitters. Source: Thermo Fisher Scientific.

Overview

Neurotransmitters and hormones are two different types of chemicals that carry signals from one part of the body to another. Both chemicals play an important part in the body's physiology. They control a variety of physical and psychological functions, including our mood, our eating patterns, our ability to learn, and our sleep cycles.

The Differences

Hormones and neurotransmitters are different chemical messengers, the former produced by the endocrine glands and the latter by the nervous system.

Hormones are usually secreted from the endocrine system and released into the bloodstream, but they act on distant target cells. Some hormones, like melatonin and cortisol, are actually produced in the brain, released in the blood, and affect other parts of the body.

On the other hand, neurotransmitters are released from the presynaptic nerve terminal in the brain. They move across the synaptic cleft, a small space between two adjacent neurons, and move to the next neuron (known as a postsynaptic neuron). There they bind to specific receptors, causing changes in the electrical properties of target cells, which can cause various postsynaptic effects. Neurotransmitters work locally and their actions are very fast.

Both hormones and neurotransmitters influence our thoughts and motivations, as well as our ability to learn and concentrate. However, neurotransmitters' actions are short-lived while hormones act for longer periods of time. Furthermore, neurotransmitters can affect both voluntary actions (eating, bathing, walking) and involuntary actions (breathing, blinking). Hormones in the endocrine system always work involuntarily.

Curious Similarities

Research in the last couple of years has demonstrated that some hormones, work like neurotransmitters independently of their classical hormone actions. The most well-studied hormones are progesterone and estrogen, which are known as steroid hormones.

Steroid hormones are typically synthesized in the endocrine gland and bind to a receptor that then binds to a specific DNA sequence, affecting gene transcription. This process is a lengthy one, which means that steroid hormones work for a prolonged period of time.

However, Progesterone and estrogen are also synthesized in the neuronal circuit, specifically in the presynaptic terminal. They then bind to the membrane and intracellular receptors followed by neurotransmitter-like action, which is very fast and short-lived. These neurotransmitters-like steroids have multiple receptors. The steroid-receptor specific functions are not yet clearly understood.

Some well-studied neuroreceptors, like dopamine and serotonin are known to possess hormonal functions. Dopamine is a neurohormone released from the hypothalamus; its main function is to block the release of prolactin, another hormone, from the pituitary gland. As a neurotransmitter released from the central nervous system, it also has many functions including roles in cognition and motor activity.

Adrenaline and noradrenaline are two molecules that differ by one carbon atom. Adrenaline, which is produced by the adrenal gland, acts as a hormone. On the other hand, noradrenaline acts as a neurotransmitter in the central nervous system.

This is just a piece of a growing body of research suggesting that many hormones work as neurotransmitters and vice-versa. The next area of research here is to determine the receptor-specificity of these molecules to understand how their function may change depending on the receptor and mode of binding.

Further Reading

S.F. Owen, et al. (2013). Nature, 500, 458-462.

B.J. Martin, et al. (2015). Nature, 520, 499-504.

Lauren M. Rudolph, et al. (2016). The J. of Neuroscience, 36, 11449-11458.

Balthazart, J. & Ball, G.F. (2006). Trends Neurosci., 29, 241-249.

# data[].attributes.attachment_link.title
Hormones and Neurotransmitters: The Differences and Curious Similarities

# data[].attributes.attachment_link.description
Neurotransmitters and hormones are two different types of chemicals that carry signals from one part of the body to another. Both chemicals play an important part in the body's physiology. They control a variety of physical and psychological functions, including our mood, our eating patterns, our ability to learn, and our sleep cycles.

# data[].attributes.body
Frontal cortex. This region orchestrates high-level functioning: maintaining attention, organization, and executive function.

# data[].attributes.body
Glutamate is a memory and learning neurotransmitter. According to Wikipedia, it is the most prevalent excitatory neurotransmitter, accounting for 90% of the synaptic (link) connections in the brain.  The history of understanding glutamate's role caught my attention. Neuroscience is such a relatively new science--though it was first suggested in 1952 after injections in dogs' brains caused seizures, it wasn't until 1980 that scientists generally agreed on its role in transmission. People were skeptical because it was so prevalent that it didn't align with the specificity of other earlier identified neurotransmitters (Wikipedia).   --Rich Powers, Germany

# data[].attributes.attachment_link.title
Neuroscience Basics: GABA and Glutamate, Animation

# data[].attributes.body
Dopamine is a neurotransmitter, meaning it sends signals from the body to the brain. It influences mood and feelings of reward and motivation. It helps regulate body movements as well.

# data[].attributes.body
If we improve the level of serotonina, we can have the right mood to better learn.

https://www.publico.pt/2018/06/28/ciencia/noticia/mais-serotonina-no-cerebro-mais-rapido-a-aprender-1836058

# data[].attributes.attachment_link.readable_text
A serotonina, um neurotransmissor que é sobretudo conhecido por ter um efeito no humor e que é o alvo de fármacos antidepressivos como o Prozac, acelera a aprendizagem. A conclusão é de uma equipa internacional de cientistas do Centro Champalimaud, em Lisboa, e da University College de Londres (UCL), que publicou na revista Nature Communications os resultados de uma série de experiências realizadas com ratinhos.

Apesar de ser muito conhecida e da (boa) fama que tem por estar associada ao bom humor e à sensação de bem-estar, a serotonina ainda é um mistério para os cientistas que tentam perceber os seus mecanismos de acção e os seus efeitos. Uma equipa de cientistas do Centro Champalimaud tem tentado esclarecer uma parte deste enigma investigando as consequências do aumento dos níveis de serotonina no cérebro dos ratinhos. Em 2015, Madalena Fonseca, Masayoshi Murakami e Zachary Mainen publicaram um artigo na revista Current Biology que concluía que o aumento da serotonina no cérebro tornava os ratinhos mais pacientes. Ou seja, quanto mais serotonina um ratinho tivesse no cérebro, maior o intervalo de tempo que conseguia esperar pacientemente por uma recompensa. Agora, o mesmo grupo de cientistas com Kiyohito Ligaya e Peter Dayan, da unidade de neurociência computacional Gatsby da UCL, deu mais um passo nesta linha de investigação concluindo que a serotonina também acelera a aprendizagem.

"O estudo publicado agora teve como ponto de partida alguns dos dados e conclusões que tirámos do estudo anterior: que, ao contrário do que se pensa habitualmente, a serotonina não parece ser simplesmente agradável ou gratificante per se, mas que têm um papel muito mais complexo", refere ao PÚBLICO a neurocientista Madalena Fonseca. Assim, a partir dos resultados já obtidos que implicaram a serotonina no aumento de plasticidade cerebral, os cientistas quiseram desta vez testar a hipótese desta substância química influenciar a tomada de decisão e comportamento, "não por ser agradável ou aversiva per se, mas indirectamente ao influenciar a rapidez com que o animal incorpora nova informação através da experiência".

E, constata Zachary Mainen num comunicado sobre o artigo publicado na Nature Communications, ficou demonstrado que a serotonina aumenta a velocidade de aprendizagem. "Quando os neurónios produtores de serotonina foram artificialmente activados com luz, os ratinhos conseguiram adaptar mais rapidamente o seu comportamento. Isto é, deram mais peso a nova informação e portanto incorporaram-na mais rapidamente nas suas decisões quando esses neurónios se encontravam activos", refere o neurocientista.

Os investigadores realizaram uma série de experiências com ratinhos que, simplificando, consistiam em colocar os animais perante uma tarefa de aprendizagem para obter água de dois bebedouros que a forneciam (ou não) com uma certa probabilidade. Primeiro, perceberam que os animais adoptavam uma de duas estratégias: ou, opção A, tentavam o bebedouro que antes lhe tinha fornecido água e se este não resultasse passavam rapidamente para o outro ou, opção B, demoravam mais tempo, recorrendo a uma memória mais a longo prazo que lhes permitia usar a experiência adquirida nas várias anteriores tentativas (e não apenas na última) e, neste caso, demoravam mais tempo a tomar a decisão.

Para perceber se e como a serotonina poderia afectar as duas estratégias, os investigadores estimularam com luz laser (através de uma técnica chamada optogenética) os neurónios produtores deste neurotransmissor no cérebro dos ratinhos. Foi assim que descobriram que a "a estimulação da serotonina aumentava a eficiência da aprendizagem baseada na história das recompensas passadas, mas apenas quando consideravam as escolhas feitas após intervalos de longa duração". Ou seja, o efeito era visível no sistema de decisão lento, a opção B.

Explorar timings e contradições

"Achamos que estes dois sistemas, ou modelos, estão sempre activos na 'cabeça do animal', mas em determinado momento, só um (ou outro) é que domina e controla o comportamento", refere Madalena Fonseca, frisando que a aprendizagem acontece nos dois sistemas. "Quando activamos os neurónios de serotonina, só o sistema lento é que aprende mais rápido (o sistema rápido continua igual). Mas como em cada momento, só um dos sistemas é que controla o comportamento do animal, só nas decisões 'tomadas' pelo sistema lento é que este efeito da serotonina é visível a nível comportamental", explica.

Para os cientistas que realizaram este estudo, a capacidade da serotonina acelerar a aprendizagem (com um inevitável impacto no comportamento) pode ajudar a explicar a maior eficácia de uma terapia para a depressão que consiste em associar os fármacos que têm como alvo este neurotransmissor (os chamados inibidores selectivos da recaptação de serotonina, ou ISRS) e terapias cognitivo-comportamentais. "O que a literatura [científica] demonstra é que os ISRS com terapias cognitivo-comportamental são mais eficazes do que qualquer uma delas separada", nota Madalena Fonseca, admitindo que um aumento da serotonina poderá acelerar a parte da terapia focada em alterar padrões de comportamento e pensamento.

O próximo passo, anuncia Madalena Fonseca, "é aprofundar o estudo da serotonina na aprendizagem (por exemplo, perceber exactamente como é a serotonina influencia a aprendizagem, se influencia todos os tipos de aprendizagem ou só alguns) e, por outro lado, perceber como é que este efeito se relaciona com outros efeitos que sabemos que a serotonina também tem, em particular o seu papel em promover a paciência".

Passo a passo, os cientistas vão desvendando os segredos da serotonina que vão além da popular sensação de bem-estar. "Ainda estamos só na ponta do icebergue, mas temos avançado bastante nos últimos anos. Em primeiro lugar, vários outros grupos confirmaram esta ideia de que a serotonina não é agradável ou graficamente per se, ou seja, a ligação entre serotonina e bem-estar não parece ser directa", confirma a neurocientista, acrescentando que os investigadores têm explorado "os vários papéis que a serotonina parece ter, mesmo os que à primeira vista pareciam contraditórios".

E conclui, deixando uma pista sobre o aparente longo alcance que a serotonina tem revelado ao exibir diferentes timings do seu efeito: "Parte da complexidade advém da serotonina actuar em diferentes escalas temporais. Por exemplo, para além de sabermos que a serotonina tem um impacto directo ('aqui e agora') no nível da 'paciência' dos animais quando esperam por recompensas, vemos, neste estudo e outros, que também influencia o comportamento a longo prazo, através de plasticidade e aprendizagem."

# data[].attributes.attachment_link.title
Mais serotonina no cérebro, mais rápido a aprender

# data[].attributes.attachment_link.description
A serotonina, um neurotransmissor que é sobretudo conhecido por ter um efeito no humor e que é o alvo de fármacos antidepressivos como o Prozac, acelera a aprendizagem. A conclusão é de uma equipa internacional de cientistas do Centro Champalimaud, em Lisboa, e da University College de Londres (UCL), que publicou na revista Nature Communications os resultados de uma série de experiências realizadas com ratinhos.

# data[].attributes.body
Serotonin
People who suffer from depression may have extremely low levels of serotonin, which explains why selective serotonin reuptake inhibitors (SSRIs), which increase serotonin levels in the brain, are essential. in the treatment of depression.

But you can naturally increase serotonin levels in your body and boost your mental health with the following five strategies:
excercise
meditation
massage
sun
nutrition

# data[].attributes.body
Neurotransmitters, or chemical mediators, are chemicals that are found in the nervous system (eg the brain), through which the transmission, modulation and amplification of nerve impulses in the synapses (the area of ​​contact between two neurons). The existence of neurotransmitters was confirmed by Otto Loewi's research, and Paton later introduced the necessary conditions for a substance to be considered a neurotransmitter:

-  to exist in final form or as a precursor in the presynaptic space
-  the synthetic enzymes should be in the same space
-  there are inactivating enzymes in the synaptic space
- stimulation of presynaptic endings to cause the release of the substance in the synaptic cleft
-  to exert an effect on the postsynaptic membrane

# data[].attributes.body
In this video we cover what the nervous system is, how it relies on nerve cells and synapses, and what a reflex arc is.

# data[].attributes.attachment_link.title
GCSE Biology - Nervous System and Reflex Arc

# data[].attributes.body
Dopamine is important for arousal, movement, mood, it keeps us going on and fulfilling our goals. So, if dopamine moves us towards desired goals, ut helps us in learning and maintaining motivation.

# data[].attributes.body
Acetylcholine is a neurotransmitter found in various areas of the central nervous system, in glandular synapses, and in muscles. It acts to stimulate muscles, activate motor neurons, promote the process of memory, is responsible for the transition from sleep to wakefulness.

It was discovered by Henry Hallett Dale in 1914. Its existence was later confirmed by Otto Loewi. They are Nobel Prize winners in physiology / medicine.

# data[].attributes.body
How are neurotransmitters linked to ADHD?
https://www.additudemag.com/adhd-neuroscience-101/
In his article about how neurotransmitters work in a brain with ADHA, Larry Silver,M.D., starts by explaining, in a simple and strainfoward way, the brain's anatomy. The brain has several regions, each one packed with with neurons (the brain's cells)  and each region is responsible for particular functions. Neurotransmitters are responsible from taking information from one region of the brain to another. As Dr. Larry Silver points out in his article "Brain scientists have found that deficiencies in specific neurotransmitters underlie many common disorders, including anxiety, mood disorders, anger-control problems, and obsessive-compulsive disorder.

ADHD was the first disorder found to be the result of a deficiency of a specific neurotransmitter — in this case, norepinephrine — and the first disorder found to respond to medications to correct this underlying deficiency. Like all neurotransmitters, norepinephrine is synthesized within the brain. The basic building block of each norepinephrine molecule is dopa; this tiny molecule is converted into dopamine, which, in turn, is converted into norepinephrine."

He continues by describing the four functional regions of the brain where ADHD  appears to involve impaired neurotransmitter activity:
"

Frontal cortex. This region orchestrates high-level functioning: maintaining attention, organization, and executive function. A deficiency of norepinephrine within this brain region might cause inattention, problems with organization, and/or impaired executive functioning.

Limbic system. This region, located deeper in the brain, regulates our emotions. A deficiency in this region might result in restlessness, inattention, or emotional volatility.

Basal ganglia. These neural circuits regulate communication within the brain. Information from all regions of the brain enters the basal ganglia, and is then relayed to the correct sites in the brain. A deficiency in the basal ganglia can cause information to “short-circuit,” resulting in inattention or impulsivity.

Reticular activating system. This is the major relay system among the many pathways that enter and leave the brain. A deficiency in the RAS can cause inattention, impulsivity, or hyperactivity.

ADHD may be the result of problems in one or more of these regions."
Most children / adolescents are prescribed medication for general treament of this disfunction; However, it is expected that further knowledge of ADHD will allow doctors to prescribe specific medication for the brain to deal with the deregulation of particular neurotransmitters in determined areas (of the brain).

# data[].attributes.attachment_link.readable_text
An expert on attention deficit and learning disabilities talks about the biology behind ADHD and why it's sometimes so difficult to diagnose and treat symptoms in children.

What Does ADHD Look Like?

In my 40 years as a child and adolescent psychiatrist, I have treated thousands of youngsters. With some children, I am able to make a quick evaluation about attention deficit hyperactivity disorder (ADHD or ADD) and outline a course of ADHD treatment.

With others - more often than I care to admit - I have to tell parents that it's not clear what is wrong. It's not that I lack the expertise or diagnostic skills. It's just that psychiatry isn't quite as far along as other medical specialties.

A pediatrician can do a throat culture and tell at once whether a child needs an antibiotic; appropriate treatment follows the diagnosis. In contrast, psychiatrists are often required to initiate a specific treatment and worry about clarifying the diagnosis later on. As I often tell parents, we must "put out the fire and blow the smoke away" before we can figure out what started the fire.

What Is ADHD vs. Another Condition?

If a child is having problems in school, he may have ADHD, but it's also possible that he has a learning disability. Or a mood disorder. Or anxiety. Sometimes what looks like ADHD is the result of family tensions.

If ADHD seems to be even a part of such a mixed clinical picture, I typically prescribe ADHD medication. If this solves the problem, terrific. But in many cases, another intervention is needed to address persistent academic, emotional, or family problems. Only weeks or months after treatment has been initiated will the full clinical picture become clear.
[Free Download: Secrets of the ADHD Brain]
I understand parents' concern about medicating their children. My clinical knowledge notwithstanding, I agonized over whether my granddaughter, who has ADHD, should be on meds. (Ultimately, we decided she should.) I have found, however, that parents often feel better about ADHD meds when they understand a bit about neurotransmitters, the remarkable compounds that govern brain function.

How Neurotransmitters Work In ADHD Brains

Before I tell you about these special brain chemicals, let me explain a bit about brain anatomy.

There are millions of cells, or neurons, densely packed into various regions of the brain. Each region is responsible for a particular function. Some regions interact with our outside world, interpreting vision, hearing, and other sensory inputs to help us figure out what to do and say. Other regions interact with our internal world - our body - in order to regulate the function of our organs.

For the various regions to do their jobs, they must be linked to one another with extensive "wiring." Of course, there aren't really wires in the brain. Rather, there are myriad "pathways," or neural circuits, that carry information from one brain region to another.

Information is transmitted along these pathways via the action of neurotransmitters (scientists have identified 50 different ones, and there may be as many as 200). Each neuron produces tiny quantities of a specific neurotransmitter, which is released into the microscopic space that exists between neurons (called a synapse), stimulating the next cell in the pathway - and no others.

How does a specific neurotransmitter know precisely which neuron to attach to, when there are so many other neurons nearby? Each neurotransmitter has a unique molecular structure - a "key," if you will - that is able to attach only to a neuron with the corresponding receptor site, or "lock." When the key finds the neuron bearing the right lock, the neurotransmitter binds to and stimulates that neuron.
[Self-Test: Could You Have a Working Memory Deficit?]
Neurotransmitter Deficiencies In ADHD Brains

Brain scientists have found that deficiencies in specific neurotransmitters underlie many common disorders, including anxiety, mood disorders, anger-control problems, and obsessive-compulsive disorder.

ADHD was the first disorder found to be the result of a deficiency of a specific neurotransmitter - in this case, norepinephrine - and the first disorder found to respond to medications to correct this underlying deficiency. Like all neurotransmitters, norepinephrine is synthesized within the brain. The basic building block of each norepinephrine molecule is dopa; this tiny molecule is converted into dopamine, which, in turn, is converted into norepinephrine.

A Four-Way Partnership

ADHD seems to involve impaired neurotransmitter activity in four functional regions of the brain:

Frontal cortex. This region orchestrates high-level functioning: maintaining attention, organization, and executive function. A deficiency of norepinephrine within this brain region might cause inattention, problems with organization, and/or impaired executive functioning.

Limbic system. This region, located deeper in the brain, regulates our emotions. A deficiency in this region might result in restlessness, inattention, or emotional volatility.

Basal ganglia. These neural circuits regulate communication within the brain. Information from all regions of the brain enters the basal ganglia, and is then relayed to the correct sites in the brain. A deficiency in the basal ganglia can cause information to "short-circuit," resulting in inattention or impulsivity.

Reticular activating system. This is the major relay system among the many pathways that enter and leave the brain. A deficiency in the RAS can cause inattention, impulsivity, or hyperactivity.

These four regions interact with one another, so a deficiency in one region may cause a problem in one or more of the other regions. ADHD may be the result of problems in one or more of these regions.

Trial and Error

We don't know which brain region is the source of ADHD symptoms. Nor can we tell whether the problem lies with a deficiency of norepinephrine itself or of its chemical constituents, dopa and dopamine. Thus, doctors must rely on clinical experience to determine which medication to try for each child, and at what dosage.

Someday, when our knowledge of the brain is greater, the diagnosis and treatment of ADHD will be more nuanced. Instead of diagnosing simply "ADHD," and prescribing a stimulant, we might be able to say, "Billy's ADHD is caused by a deficiency of dopa in the frontal cortex, so he needs medication A," or "Mary has a type of ADHD caused by a deficiency of dopamine in the limbic system, so she needs medication B," or "José has ADHD caused by a deficiency of norepinephrine in the reticular activating system, and he needs medication C."

What do ADHD medications do? In simple terms, they raise the level of norepinephrine within the brain. (Stimulants work by causing the brain to synthesize more norepinephrine; nonstimulants by slowing the rate at which norepinephrine is broken down.) Once the level is where it should be, the brain functions normally, and the individual becomes less hyperactive, inattentive, and/or impulsive. Once the drug wears off, the level falls - and symptoms return.

And so we come to the conclusion of Neuroscience 101. I hope you have a greater knowledge of, and appreciation for, the human brain. I also hope you have a better understanding of neurotransmitters and how they are linked to ADHD.

In years to come, I'm sure we will gain a more comprehensive understanding of ADHD - and new medications that will be more effective than those we have now. I can't wait.
[Self-Test: Signs of Emotional Hyperarousal] Larry Silver,M.D., is a member of ADDitude's ADHD Medical Review Panel.
Updated on December 19, 2019

# data[].attributes.attachment_link.description
An expert on attention deficit and learning disabilities talks about the biology behind ADHD and why it's sometimes so difficult to diagnose and treat symptoms in children. In my 40 years as a child and adolescent psychiatrist, I have treated thousands of youngsters.

# data[].attributes.body
Neurotransmitters are chemical messengers in the body. Their job is to transmit signals from nerve cells to target cells. These target cells may be in muscles, glands, or other nerves.

The brain needs neurotransmitters to regulate many necessary functions, including:

heart rate

breathing

sleep cycles

digestion

mood

concentration

appetite

muscle movement

# data[].attributes.attachment_caption
Does serotonin or dopamine make you happy?

# data[].attributes.body
These hormones or neurotransmitters are involved in promoting a happy mood and positive feelings, and you might know them by different names too. For example, serotonin is also called the happiness hormone, dopamine is a feel-good hormone, and oxytocin is the cuddle hormone.

# data[].attributes.body
ADHD is one of the most common disorder in children. It affects all the life of a person, not only the school.
One of the maximum expert in the study of ADHD is Doct. Russe Barclay: http://www.russellbarkley.org/factsheets.html
In his studies it is clearly explained the roles of neurotransmitters and the brain parts that contribute in developing the disease.

# data[].attributes.attachment_link.title
Dr. Russell A. Barkley - Dedicated to Education and Research on ADHD

# data[].attributes.attachment_link.description
Russell A. Barkley, Ph.D. Dedicated to Education and Research on ADHD

# data[].attributes.body
Serotonin:
- is the key neurotransmitter that stabilizes our mood, feelings of well-being, and happiness.
- helps with sleeping, eating, and digestion.
-low levels of serotonin in the brain may cause depression, anxiety, and sleep trouble.

# data[].attributes.headline
Nikolaos Mpakos, Greece                                           Dopamine, Rewarding and Learning

# data[].attributes.subject
Nikolaos Mpakos, Greece                                           Dopamine, Rewarding and Learning

# data[].attributes.body
During teaching and learning process always arises the question: why some of the students hold onto the information they are taught while others do not? The answer has to do with dopamine which influences the retention of information and is considered as the “save button” of the brain. Dopamine, among its other functions, is released in the brain when we are rewarded. It is also released when a person gambles or engages in a new exciting adventure. For people, learning is like an adventure or a rewarding activity, and dopamine levels increase in the brain to help them retain the new information in order to reward and feel self-content. In case of disorders in dopamine levels the new information seems unstabilized and poorly anchored in brain and is lost.

Dopamine activate the “reward center” of the brain, those regions that increase motivation and interest. More dopamine released, more motivation and interest is recorded and the better one remembers. The “reward center” is located where good things we enjoy in our life or interesting and useful information we remember. “It helps us to stay focused and repeat activities that were reinforced through positive outcomes”.

In order a teacher to increase the students’ dopamine levels he has “to make learning: new, exciting and rewarding”.

·         NEW. In order to do so, he has to adopt new learning material (e.g. new books), to use novel ways of teaching (e.g. group work), to present information with new ways (e.g. use of ICT).

·         EXCITING. In order to make learning exciting, a teacher can use open questions and problems, cooperative activities, research activities and projects focusing on students’  interests, out of school teaching e.t.c.

·         REINFORCEMENT. It is considered as “one of the greatest memory enhancers”. Activate the less devoted students, encourage them, compliment and reward them despite their success. By reinforcement, “students will remember information even though they might be ordinarily very poor at attending in class or forgetful”. Carefully used, reinforcement “is one of the greatest memory enhancers in the brain”.

“Dopamine can be addictive and our goal as teachers is to get our students addicted to learning”.

Based on: Burns, M. (2012). Dopamine and Learning: What The Brain’s Reward Center Can Teach Educators. Retrived 21/11/21 from: https://tinyurl.com/4ej7m5ax

# data[].attributes.body
https://www.ncbi.nlm.nih.gov/books/NBK10960/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5986471/
Foods are natural sources of substances that may exert crucial effects on the nervous system in humans. Some of these substances are the neurotransmitters (NTs) acetylcholine (ACh), the modified amino acids glutamate and γ-aminobutyric acid (GABA), and the biogenic amines dopamine, serotonin (5-HT), and histamine. In neuropsychiatry, progressive integration of dietary approaches in clinical routine made it necessary to discern the more about some of these dietary NTs. Relevant books and literature from PubMed and Scopus databases were searched for data on food sources of Ach, glutamate, GABA, dopamine, 5-HT, and histamine. Different animal foods, fruits, edible plants, roots, and botanicals were reported to contain NTs. These substances can either be naturally present, as part of essential metabolic processes and ecological interactions, or derive from controlled/uncontrolled food technology processes. Ripening time, methods of preservation and cooking, and microbial activity further contributes to NTs. Moreover, gut microbiota are considerable sources of NTs. However, the significance of dietary NTs intake needs to be further investigated as there are no significant data on their bioavailability, neuronal/non neuronal effects, or clinical implications. Evidence-based interventions studies should be encouraged.

# data[].attributes.attachment_link.readable_text
By the 1950s, the list of neurotransmitters (defined by the criteria described in Box A) had expanded to include four amines-epinephrine, norepinephrine, dopamine, and serotonin-in addition to ACh. Over the following decade, three amino acids-glutamate, γ-aminobutyric acid (GABA), and glycine-were also shown to be neurotransmitters. Subsequently, other small molecules were added to the list, and considerable evidence now suggests that histamine, aspartate, and ATP should be included ( Figure 6.3). The most recent class of molecules discovered to be transmitters are a large number of polypeptides; since the 1970s, more than 100 such molecules have been shown to meet at least some of the criteria outlined in Box A.

For purposes of discussion, it is useful to separate this variety of agents into two broad categories based simply on their size ( Figure 6.3). Neuropeptides are relatively large transmitter molecules composed of 3 to 36 amino acids ( Figure 6.4). Individual amino acids, such as glutamate and GABA, as well as the transmitters acetylcholine, serotonin, and histamine, are much smaller than neuropeptides and have therefore come to be called small-molecule neurotransmitters. Within the category of small-molecule neurotransmitters, the biogenic amines ( dopamine, norepinephrine, epinephrine, serotonin, and histamine) are often discussed separately because of their similar chemical properties and postsynaptic actions.

# data[].attributes.attachment_link.title
Two Major Categories of Neurotransmitters

# data[].attributes.attachment_link.description
By the 1950s, the list of neurotransmitters (defined by the criteria described in Box A) had expanded to include four amines-epinephrine, norepinephrine, dopamine, and serotonin-in addition to ACh. Over the following decade, three amino acids-glutamate, γ-aminobutyric acid (GABA), and glycine-were also shown to be neurotransmitters.

# data[].attributes.body
Glutamate. Glutamate is the most abundant excitatory neurotransmitter in the vertebrate nervous system. It helps in cognitive function, memory, and learning.  Glutamate plays important role in the regulation of growth cones and synaptogenesis during brain development.

# data[].attributes.attachment_link.readable_text
GLUTAMATE'S ROLE IN THE BRAIN

Glutamate is an important neurotransmitter present in over 90% of all brain synapses and is a naturally occurring molecule that nerve cells use to send signals to other cells in the central nervous system. Glutamate plays an essential role in normal brain functioning and its levels must be tightly regulated. Abnormalities in glutamate function can disrupt nerve health and communication, and in extreme cases may lead to nerve cell death. Nerve cell dysfunction and death leads to devastating diseases, including ataxia, ALS, GAD and other neurological and neuropsychiatric disorders. Glutamate clearance is necessary for proper synaptic activity and to prevent neuronal damage from excessive activation of glutamate receptors. Excitatory amino-acid transporters, or EAATs, regulate glutamate clearance, and are responsible for most of the glutamate uptake within the brain. Modulating glutamate also has the potential to be neuroprotective and increase the release of neurotrophic factors, including brain derived neurotrophic factor, or BDNF, which are endogenous molecules that help to support the survival of existing neurons, and encourage the growth and differentiation of new neurons and synapses.

Glutamate must be tightly regulated once released from a pre-synaptic neuron and acts as a signaling neurotransmitter to stimulate the post-synaptic neuron via stimulation of glutamate receptors (e.g., NMDA, AMPA or Kainate receptors). Glial cells surrounding the synaptic junction are predominantly responsible for clearing glutamate through transporters, the EAATs. There are five distinct types of glutamate transporters. (1) As depicted in the green-colored glial cell marked with "1" on the right side of figure, BHV-0223 and Troriluzole increase the activity of the EAATs to increase the clearance of glutamate and decrease glutamate release from the pre-synaptic neuron. Troriluzole and BHV-0223 also inhibit presynaptic ion channels that may inhibit the release of glutamate from presynaptic neurons. (2) As depicted in the purple-colored postsynaptic neuron to the bottom of the figure marked with "2", BHV-5000 blocks glutamate signaling that is mediated by post-synaptic NMDA receptors. Modulating glutamate also has the potential to be neuroprotective and increase the release of neurotrophic factors, including brain derived neurotrophic factor, or BDNF, which are endogenous molecules that help to support the survival of existing neurons, and encourage the growth and differentiation of new neurons and synapses.

# data[].attributes.attachment_link.description
GLUTAMATE'S ROLE IN THE BRAIN Glutamate is an important neurotransmitter present in over 90% of all brain synapses and is a naturally occurring molecule that nerve cells use to send signals to other cells in the central nervous system. Glutamate plays an essential role in normal brain functioning and its levels must be tightly regulated.

# data[].attributes.body
Learning and memory being highly specialized process of human brain involves complex interaction between neurotransmitters and cellular events. Over the years, the understandings of these processes have been evolving from psychological, neurophysiological, and pharmacological perspectives. The most widely appraised model of learning and memory involves attention, acquisition, storage and retrieval. Each of these events involve interplay of neurotransmitters such as dopamine, acetylcholine, norepinephrine, N-methyl-d-aspartic acid, gamma-aminobutyric acid, though preponderance of specific neurotransmitter have been documented. The formation of long-term memory involves cellular events with neuroplasticity. Further, dopamine is documented to play crucial role in the process of forgetting. Understanding of the processes of learning and memory not only facilitates drug discovery, but also helps to understand actions of several existing drugs. In addition, it would also help to enhance psychological interventions in children with learning disabilities. Thus, the review intends to summarize role of neurotransmitters and neuromodulators during different phases of learning and memory.
https://pesquisa.bvsalud.org/portal/resource/pt/sea-200469

# data[].attributes.attachment_link.readable_text
Learning and memory being highly specialized process of human brain involves complex interaction between neurotransmitters and cellular events. Over the years, the understandings of these processes have been evolving from psychological, neurophysiological, and pharmacological perspectives. The most widely appraised model of learning and memory involves attention, acquisition, storage and retrieval. Each of these events involve interplay of neurotransmitters such as dopamine, acetylcholine, norepinephrine, N-methyl-d-aspartic acid, gamma-aminobutyric acid, though preponderance of specific neurotransmitter have been documented. The formation of long-term memory involves cellular events with neuroplasticity. Further, dopamine is documented to play crucial role in the process of forgetting. Understanding of the processes of learning and memory not only facilitates drug discovery, but also helps to understand actions of several existing drugs. In addition, it would also help to enhance psychological interventions in children with learning disabilities. Thus, the review intends to summarize role of neurotransmitters and neuromodulators during different phases of learning and memory.

# data[].attributes.attachment_link.title
Neurotransmitters and neuromodulators involved in learning and memory | IMSEAR

# data[].attributes.attachment_link.description
Learning and memory being highly specialized process of human brain involves complex interaction between neurotransmitters and cellular events. Over the years, the understandings of these processes have been evolving from psychological, neurophysiological, and pharmacological perspectives. The most widely appraised model of learning and memory involves attention, acquisition, storage and retrieval.

# data[].attributes.body
"This brain research demonstrates that superior learning takes place when classroom experiences are motivating and engaging. Positive motivation impacts brain metabolism, conduction of nerve impulses through the memory areas, and the release of neurotransmitters that increase executive function and attention. Relevant lessons help students feel that they are partners in their education, and they are engaged and motivated."
Have you ever noticed how smarter and humourous you may be when you are surrounded by people who make you feel confident, safe, loved? And how dumb you consider yourself when feeling insecure?

# data[].attributes.attachment_link.description
Edutopia is a free source of information, inspiration, and practical strategies for learning and teaching in preK-12 education. We are published by the George Lucas Educational Foundation, a nonprofit, nonpartisan organization.

# data[].attributes.body
GLUTAMATE

Glutamate is important element in memory formation. It has important role in mechanism of memory and learning called long-term potentiation (LPT).

LTP is a form of synaptic plasticity, biochemical process through which synapses respond to patterns of activity what affects on ability of the brain to change and adapt to new information.

# data[].attributes.attachment_link.title
Neuroscience Basics: GABA and Glutamate, Animation

# data[].attributes.body
Mariana, Romania
Researchers have shown that the alcohol reduces the stress, at least for a while, by accelerating the activity of the neurotransmitter called GABA. Thus, the more alcohol a person consumes, the more his brain receives signals emitted by it, inducing a state of relaxation similar to that caused by valium or xanax. Alcohol also lowers the level of glutamate, the most important molecule in brain tissue. A third substance released into the body when alcohol is consumed is dopamine, the substance responsible for various addictions. Other neurotransmitters released during alcohol consumption are opioids, also called endorphins that cause well-being, which causes the person to consume even more alcohol.

# data[].attributes.body
If neurotransmission is impaired, diseases such as Alzheimer's, Parksonson's disease, autism, anxiety, depression, epilepsy, schizophrenia may occur.

# data[].attributes.headline
NEUROTRANSMITTERS AND COGNITIVE FUNCTIONS -DANIELA BALOSACHE, ROMANIA

# data[].attributes.subject
NEUROTRANSMITTERS AND COGNITIVE FUNCTIONS -DANIELA BALOSACHE, ROMANIA

# data[].attributes.body
Learning and all the psychological processes of the brain are influenced by various neurotransmitters. There are 7 important neurotransmitters in the brain:

-        acetylcholine

-        dopamine

-        gamma-aminobutyric acid (GABA)

-        glutamate

-        histamine

-        norepinephrine

-        serotonin

Acetylcholine (ACh) alters neuronal excitability and coordinates the firing of groups of neurons. Acetylcholine may enhance the encoding of memory by enhancing the influence of feedforward afferent input to the cortex. It triggers the working memory, attention, episodic memory, and spatial memory function.

Dopamine influences  the cognitive function. It acts directly on the output neurons of the prefrontal cortex, which are involved in processing, sorting, and assembling information about the outside world.

Gamma-aminobutyric acid (GABA) is an amino acid that functions as the primary inhibitory neurotransmitter for the central nervous system (CNS). It functions to reduce neuronal excitability by inhibiting nerve transmission.

Glutamate is the most common excitatory neurotransmitter, found throughout your brain and spinal cord. Glutamate has many essential functions, including early brain development, cognition, learning and memory.

Histamine is a mediator of "wakefulness" and its activity is necessary to maintain wakefulness, alertness, and reaction time. It can be also a key factor in addictive behaviors and degenerative disease such as Parkinson’s diseases and multiple sclerosis.

Together with adrenaline, norepinephrine increases heart rate and blood pumping from the heart. he general function of norepinephrine is to mobilize the brain and body for action. It also increases blood pressure and helps break down fat and increase blood sugar levels to provide more energy to the body.Norepinephrine plays a role in a number of functions including memory, attention, stress reactions, energy levels, and the regulation of emotions.

Serotonin is the key neurotransmitter that stabilizes our mood, feelings of well-being, and happiness. Serotonin also helps with sleeping, eating, and digestion.
Low levels of serotonin in the brain may cause depression, anxiety, and sleep trouble.

# data[].attributes.body
Neurotransmitters are often referred to as the body's chemical messengers. They are the molecules used by the nervous system to transmit messages between neurons, or from neurons to muscles. Communication between two neurons happens in the synaptic cleft (the small gap between the synapses of neurons).What are some examples of neuromodulation?

In addition to chronic pain relief, some examples of neuromodulation therapies employed around the world include deep brain stimulation for essential tremor, Parkinson's disease, dystonia, epilepsy and psychiatric disorders such as depression, obsessive compulsive disorder and Tourette syndrome

# data[].attributes.body
GABA is a non-protein amino acid that functions as an inhibitory neurotransmitter throughout the CNS.
Inhibitory neurons make neurons less likely to fire. Therefore, GABA reduces a neuron's tendency to produce an action potential (neuron stimulation), making neurons less likely to excite nearby neurons.
When an action potential arrives at the axon terminal of a gabaminergic neuron, it causes the release of GABA into the synaptic cleft. Then GABA gets attached in the post-synaptic receptors, the receptors open chloride ion channels and due to the fact that negatively charged ions rush into the post-synaptic neuron, causes a highly negative inside-of—the cell environment, making it less likely to fire action potential.

In the brain, GABA activity has a calming effect. In the spinal cord, this process allows for sensory information integration and helps to create smooth movements.

Disorders caused by GABA malfunction are associated with mental health, such as anxiety disorders, schizophrenia, Autism Spectrum Disorder (ADS), depression and some physical disorders.

In terms of education, anxiety and stress during a test performance, or during a subject that in the student’s mind is considered to be a difficult one (math anxiety), are of the main reasons a student creates a negative attitude towards a specific subject or school in general. A balance in GABA is required, so that phenomena like stress and anxiety could be eliminated from school life.

# data[].attributes.body
Understanding how our brain works and how all the neurotransmitters are constantly affecting our interactions with the world is crucial. The chemicals in the brain play an enormous role in the classroom and the learning experiences that we design every day for our students. Some recommendations are:
Novelty: using new and original ideas to introduce concepts raises students’ attention and helps the new ideas stand out in a sea of everyday information. By doing this, students become mentally engaged in the concept, process, or skill to be learned.

Sensory Learning: multisensory learning uses all of the senses (taste, smell, touch, sight, hearing, and movement) to help students engage with the content in more than one way. Field trips, realia, manipulatives, experimentation, and hands-on exploration are a few examples.

Active Playful Learning: try designing learning experiences that require students actively participating in activities that encourage playful exploration of problems and new ideas. It also means game-based learning and creating a playful environment that encourages competition and collaboration.

Storytelling: storytelling represents a wonderful way to help our students develop a deep understanding of content lessons as well as making learning meaningful. Stories can create a sense of wonder, and children have an innate love for them. They tap into our emotions.

Emotions: emotions are like the glue that helps ideas connect and stick in our minds. Emotional and personal content allows students to connect with new concepts and ideas on a deeper, more intrinsic level.

Anchoring: visual and physical anchors keep learning accessible to students. They activate prior knowledge and facilitate connections as new learning happens. Charts, posters, and word walls are great tools.

Organization and Chunking: presenting new information in an organized manner and divided into meaningful chunks reduces the cognitive load of a lesson and facilitates learning. Chunking is even more powerful when the students create their own categories for organization.

# data[].attributes.body
When people use drugs, they also affect neurotransmietters. The first response is that the drugs increase the amount of neurotransmitters. So the person feels excited. But our body downregulates it very fast- it reduces the amount of receptors for them. So the starting exciting effect is gone. A person then applies more drugs to get the inital effect . But this could never be achived again as we don't have enough receptors for neurotransmitters to bond, so the excitement is less. so a person feels less even in normal situations that before. What a drug addict does is that he/she taking more and more drugs and intoxicates his body to the point of death and yet the inital effect can't be acomplished any more.

# data[].attributes.body
Neurotransmitters are chemical messengers in the body. Their job is to transmit signals from nerve cells to target cells. These target cells may be in muscles, glands, or other nerves. The brain needs neurotransmitters to regulate many necessary functions, including: heart rate.

Neuromodulators are substances that do not directly activate ion-channel receptors but that, acting together with neurotransmitters, enhance the excitatory or inhibitory responses of the receptors. It is often impossible to determine, in the presence of many substances, which are transmitters and which are modulators.

# data[].attributes.body
'Neurotransmitters play a major role in everyday life and functioning. Scientists do not yet know exactly how many neurotransmitters exist, but more than 60 distinct chemical messengers have been identified.

Neurotransmitters can be classified by their function:

Excitatory neurotransmitters: These types of neurotransmitters have excitatory effects on the neuron, meaning they increase the likelihood that the neuron will fire an action potential. Some of the major excitatory neurotransmitters include epinephrine and norepinephrine.

Inhibitory neurotransmitters: These types of neurotransmitters have inhibitory effects on the neuron; they decrease the likelihood that the neuron will fire an action potential. Some of the major inhibitory neurotransmitters include serotonin and gamma-aminobutyric acid (GABA).

Modulatory neurotransmitters: These neurotransmitters, often referred to as neuromodulators, are capable of affecting a larger number of neurons at the same time. These neuromodulators also influence the effects of other chemical messengers. Where synaptic neurotransmitters are released by axon terminals to have a fast-acting impact on other receptor neurons, neuromodulators diffuse across a larger area and are more slow-acting.

Neurotransmitters play a critical role in neural communication, influencing everything from involuntary movements to learning to mood. This system is both complex and highly interconnected. Neurotransmitters act in specific ways, but they can also be affected by diseases, drugs, or even the actions of other chemical messengers.'

# data[].attributes.body
'Billions of neurotransmitter molecules work constantly to keep our brains functioning, managing everything from our breathing to our heartbeat to our learning and concentration levels. They can also affect a variety of psychological functions such as fear, mood, pleasure, and joy. (...)
Glutamate: The most plentiful neurotransmitter found in the nervous system, glutamate plays a role in cognitive functions such as memory and l earning. (...)
Acetylcholine: This is the only neurotransmitter in its class. Found in both the central and peripheral nervous systems, it is the primary neurotransmitter associated with motor neurons. It plays a role in muscle movements as well as memory and learning.'

# data[].attributes.attachment_link.readable_text
A neurotransmitter is a chemical messenger that carries, boosts, and balances signals between neurons (also known as nerve cells) and target cells throughout the body. These target cells may be in glands, muscles, or other neurons.

Billions of neurotransmitter molecules work constantly to keep our brains functioning, managing everything from our breathing to our heartbeat to our learning and concentration levels. They can also affect a variety of psychological functions such as fear, mood, pleasure, and joy.

How Neurotransmitters Work

In order for neurons to send messages throughout the body, they need to be able to communicate with one another to transmit signals. However, neurons are not simply connected to one another. At the end of each neuron is a tiny gap called a synapse and in order to communicate with the next cell, the signal needs to be able to cross this small space. This occurs through a process known as neurotransmission.

In most cases, a neurotransmitter is released from what's known as the axon terminal after an action potential has reached the synapse, a place where neurons can transmit signals to each other.

When an electrical signal reaches the end of a neuron, it triggers the release of small sacs called vesicles that contain the neurotransmitters. These sacs spill their contents into the synapse, where the neurotransmitters then move across the gap toward the neighboring cells. These cells contain receptors where the neurotransmitters can bind and trigger changes in the cells.

After release, the neurotransmitter crosses the synaptic gap and attaches to the receptor site on the other neuron, either exciting or inhibiting the receiving neuron depending on what the neurotransmitter is.

Sometimes neurotransmitters can bind to receptors and cause an electrical signal to be transmitted down the cell (excitatory). In other cases, the neurotransmitter can actually block the signal from continuing, preventing the message from being carried on (inhibitory).

Inactivation of Neurotransmitters

So what happens to a neurotransmitter after its job is complete? Once the neurotransmitter has had the designed effect, its activity can be stopped by three mechanisms:

Degradation: An enzyme changes the structure of the neurotransmitter so it can't be recognized by the receptor

Diffusion: The neurotransmitter drifts away from the receptor

Reuptake: The whole neurotransmitter molecule is taken back up by the axon of the neuron that released it

The actual identification of neurotransmitters can actually be quite difficult. While scientists can observe the vesicles containing neurotransmitters, figuring out what chemicals are stored in the vesicles is not quite so simple.

Because of this, neuroscientists have developed a number of guidelines for determining whether or not a chemical should be defined as a neurotransmitter:﻿﻿

Presence of the chemical within the cell. The chemical is either synthesized in the neuron or otherwise found in it.

Stimulus-dependent release. It is released in appropriate quantities by the neuron upon stimulation.

Action on postsynaptic cell. The chemical must be released by the presynaptic neuron, and the postsynaptic neuron must contain receptors that the chemical will bind to.

Mechanism for removal. A specific mechanism exists to remove the chemical from its site of activation after its work is done.

Classification

Neurotransmitters play a major role in everyday life and functioning. Scientists do not yet know exactly how many neurotransmitters exist, but more than 60 distinct chemical messengers have been identified.﻿﻿

Neurotransmitters can be classified by their function:﻿﻿

Excitatory neurotransmitters: These types of neurotransmitters have excitatory effects on the neuron, meaning they increase the likelihood that the neuron will fire an action potential. Some of the major excitatory neurotransmitters include epinephrine and norepinephrine.

Inhibitory neurotransmitters: These types of neurotransmitters have inhibitory effects on the neuron; they decrease the likelihood that the neuron will fire an action potential. Some of the major inhibitory neurotransmitters include serotonin and gamma-aminobutyric acid (GABA).

Modulatory neurotransmitters: These neurotransmitters, often referred to as neuromodulators, are capable of affecting a larger number of neurons at the same time. These neuromodulators also influence the effects of other chemical messengers. Where synaptic neurotransmitters are released by axon terminals to have a fast-acting impact on other receptor neurons, neuromodulators diffuse across a larger area and are more slow-acting.

There are a number of different ways to classify and categorize neurotransmitters. In some instances, they are simply divided into monoamines, amino acids, and peptides.﻿﻿

Neurotransmitters can also be categorized into one of six types:

Amino Acids

Gamma-aminobutyric acid (GABA): This naturally occurring amino acid acts as the body's main inhibitory chemical messenger. GABA contributes to vision, motor control, and plays a role in the regulation of anxiety. Benzodiazepines, which are used to help treat anxiety, function by increasing the efficiency of GABA neurotransmitters, which can increase feelings of relaxation and calm.

Glutamate: The most plentiful neurotransmitter found in the nervous system, glutamate plays a role in cognitive functions such as memory and learning. Excessive amounts of glutamate can cause excitotoxicity resulting in cellular death. This excitotoxicity caused by glutamate build-up is associated with some diseases and brain injuries including Alzheimer's disease﻿﻿ , stroke, and epileptic seizures.

Oxytocin: This powerful hormone acts as a neurotransmitter in the brain. It is produced by the hypothalamus and plays a role in social recognition, bonding, and sexual reproduction.﻿﻿ Synthetic oxytocin such as Pitocin is often used as an aid in labor and delivery. Both oxytocin and Pitocin cause the uterus to contract during labor.

Endorphins: These neurotransmitters than inhibit the transmission of pain signals and promote feelings of euphoria. These chemical messengers are produced naturally by the body in response to pain, but they can also be triggered by other activities such as aerobic exercise.﻿﻿ For example, experiencing a "runner's high" is an example of pleasurable feelings generated by the production of endorphins.

Monoamines

Epinephrine: Also known as adrenaline, epinephrine is considered both a hormone and a neurotransmitter. Generally, epinephrine is a stress hormone that is released by the adrenal system. However, it functions as a neurotransmitter in the brain.﻿﻿

Norepinephrine:This naturally occurring chemical is a neurotransmitter that plays an important role in alertness is involved in the body's fight or flight response. Its role is to help mobilize the body and brain to take action in times of danger or stress. Levels of this neurotransmitter are typically lowest during sleep and highest during times of stress.

Histamine: This organic compound acts as a neurotransmitter in the brain and spinal cord.﻿﻿ It plays a role in allergic reactions and is produced as part of the immune system's response to pathogens.

Dopamine: Commonly known as the feel-good neurotransmitter, dopamine is involved in reward, motivation, and additions.﻿﻿ Several types of addictive drugs increase dopamine levels in the brain. This chemical messenger also plays an important role in the coordination of body movements. Parkinson's disease, which is a degenerative disease that results in tremors and motor movement impairments, is caused by the loss of dopamine-generating neurons in the brain.

Serotonin: A hormone and neurotransmitter, serotonin plays an important role in regulating and modulating mood, sleep, anxiety, sexuality, and appetite. Selective serotonin reuptake inhibitors (SSRIs) are a type of antidepressant medication commonly prescribed to treat depression, anxiety, panic disorder, and panic attacks. SSRIs work to balance serotonin levels by blocking the reuptake of serotonin in the brain, which can help improve mood and reduce feelings of anxiety.﻿﻿

Adenosine: This naturally occurring chemicalacts as a neuromodulator in the brain and is involved in suppressing arousing and improving sleep.

Adenosine triphosphate (ATP): Considered to be the energy currency of life, ATP acts as a neurotransmitter in the central and peripheral nervous systems.﻿﻿ It plays a role in autonomic control, sensory transduction, and communication with glial cells. Research suggests it may also have a part in some neurological problems including pain, trauma, and neurodegenerative disorders.

Gasotransmitters

Nitric oxide: This compound plays a role in affecting smooth muscles, relaxing them to allow blood vessels to dilate and increase blood flow to certain areas of the body.

Carbon monoxide: This colorless, odorless gas can have toxic and potentially fatal effects when people are exposed to high levels of the substance. However, it is also produced naturally by the body where it acts as a neurotransmitter that helps modulate the body's inflammatory response.﻿﻿

Acetylcholine

Acetylcholine: This is the only neurotransmitter in its class. Found in both the central and peripheral nervous systems, it is the primary neurotransmitter associated with motor neurons.﻿﻿ It plays a role in muscle movements as well as memory and learning.

When Neurotransmitters Do Not Work Right

As with many of the body's processes, things can sometimes go awry. It is perhaps not surprising that a system as vast and complex as the human nervous system would be susceptible to problems.

A few of the things that might go wrong include:

Neurons might not manufacture enough of a particular neurotransmitter

Neurotransmitters may be reabsorbed too quickly

Too many neurotransmitters may be deactivated by enzymes

Too much of a particular neurotransmitter may be released

When neurotransmitters are affected by disease or drugs, there can be a number of different adverse effects on the body. Diseases such as Alzheimer's, epilepsy, and Parkinson's are associated with deficits in certain neurotransmitters.

Health professionals recognize the role that neurotransmitters can play in mental health conditions, which is why medications that influence the actions of the body's chemical messengers are often prescribed to help treat a variety of psychiatric conditions.

For example, dopamine is associated with such things as addiction and schizophrenia. Serotonin plays a role in mood disorders including depression and OCD.﻿﻿ Drugs, such as SSRIs, may be prescribed by physicians and psychiatrists to help treat symptoms of depression or anxiety.

Drugs That Influence Neurotransmitters

Perhaps the greatest practical application for the discovery and detailed understanding of how neurotransmitters function has been the development of drugs that impact chemical transmission. These drugs are capable of changing the effects of neurotransmitters, which can alleviate the symptoms of some diseases.

Agonists vs Antagonists: Some drugs are known as agonists and function by increasing the effects of specific neurotransmitters. Other drugs and referred to as antagonists and act to block the effects of neurotransmission.﻿﻿

Direct vs Indirect Effects:These neuro-acting drugs can be further broken down based on whether they have a direct or indirect effect. Those that have a direct effect work by mimicking the neurotransmitters because they are very similar in chemical structure. Those that have an indirect impact work by acting on the synaptic receptors.

Drugs that can influence neurotransmission include medications used to treat illness including depression and anxiety, such as SSRIs, tricyclic antidepressants, and benzodiazepines.

Illicit drugs such as heroin, cocaine, and marijuana also have an effect on neurotransmission. Heroin acts as a direct-acting agonist, mimicking the brain's natural opioids enough to stimulate their associated receptors. Cocaine is an example of an indirect-acting drug that influences the transmission of dopamine.﻿﻿

A Word From Verywell

Neurotransmitters play a critical role in neural communication, influencing everything from involuntary movements to learning to mood. This system is both complex and highly interconnected. Neurotransmitters act in specific ways, but they can also be affected by diseases, drugs, or even the actions of other chemical messengers.

# data[].attributes.attachment_link.title
How Neurotransmitters Work and What They Do

# data[].attributes.attachment_link.description
A neurotransmitter is a chemical messenger that carries, boosts, and balances signals between neurons (also known as nerve cells) and target cells throughout the body. These target cells may be in glands, muscles, or other neurons. Billions of neurotransmitter molecules work constantly to keep our brains functioning, managing everything from our breathing to our heartbeat to our learning and concentration levels.

# data[].attributes.body
Disorders in the transmission between synapses (nerve cells) can have devastating consequences, even if it is momentary and short-term (acute) or long-term (chronic). Neurological diseases such as Alzheimer's, autism, epilepsy and many psychiatric brain-based diseases such as schizophrenia, depression and anxiety occur as a result of damage to the nerves in our brain for various reasons.

One of the exciting developments in the field of molecular cell biology in the 21st century is that scientists have observed the different transport substances (neurotransmitters) involved in chemical transmission and what functions these substances play. Today, the functions of many chemicals in our nerves such as serotonin, noradrenaline (norepinephrine), dopamine, endorphin, oxytocin, vasopressin, acetylcholine, GABA, histamine are known. Of course, there are still veils of mystery about the reactions and pathways in which these chemicals work.

# data[].attributes.headline
Dopamine serves many purposes, eg. it activates the reward system, provides with pleasure, empowers emotional responses and enables to see rewards and take action to obtain them. It is the chemical that makes us feel good and motivates us to achieve goals. It also seems to be released when our curiosity has been sparked. So, if students show high interest in the information being presented, it can be attributed to high amounts of dopamine being produced. You tend to remember events that you enjoy! Therefore, if we want to increase student engagement and retention of information, we need to use innovative ways to present that information by using more exciting learning methods and strategies.

# data[].attributes.subject
Dopamine serves many purposes, eg. it activates the reward system, provides with pleasure, empowers emotional responses and enables to see rewards and take action to obtain them. It is the chemical that makes us feel good and motivates us to achieve goals. It also seems to be released when our curiosity has been sparked. So, if students show high interest in the information being presented, it can be attributed to high amounts of dopamine being produced. You tend to remember events that you enjoy! Therefore, if we want to increase student engagement and retention of information, we need to use innovative ways to present that information by using more exciting learning methods and strategies.

# data[].attributes.body
Roxanthi Nikou

# data[].attributes.body
Katecholamines, amino acid derivatives of tyrosine, including adrenaline (epinephrine), noradrenaline (norepinephrine) and dopamine. Catecholamines are produced in the nervous system and in the adrenal medulla, and among their main functions are the regulation of metabolism, action on the circulatory system and defense against the effects of stress (adrenaline) and neurotransmitter function in the central and autonomic nervous system (dopamine and noradrenaline).

# data[].attributes.body
Neurotransmitters are substances used by neurons to communicate with each other and with the tissues on which they will act (called target tissues or target tissues) in the process of synaptic transmission (neurotransmission).

Neurotransmitters are synthesized and released in nerve endings at the level of the synaptic cleft. After release, neurotransmitters bind to receptor proteins on the cell membrane of the target tissue. The target tissue can then be excited, inhibited, or functionally modified.

There are more than 40 neurotransmitters in the human nervous system; some of the most important are: acetylcholine, norepinephrine, dopamine, gamma-aminobutyric acid (GABA), glutamate, serotonin, and histamine.

# data[].attributes.body
Learning and memory being highly specialized process of human brain involves complex interaction between neurotransmitters and cellular events.