Linda Buck is a little nosey by Isabelle Smith

Individual - Linda Buck

smith15517 — 2024-02-16 20:38:48 UTC

Linda Buck, born in Seattle in 1947, never envisioned herself becoming a scientist, even though she was naturally curious like one. Her parents, her father being an electrical engineer and her mother a homemaker, fostered her curiosity by enjoying puzzles and inventions. This upbringing likely influenced her career choice, as she sees science as a form of solving puzzles. They also encouraged her exploration, critical thinking, and expected her to make a meaningful contribution to society. She ended up pursuing biology after a class in immunology sparked her interest. Buck's pivotal moment came when she pondered the unsolved puzzle of olfaction, leading her to search for odor receptors. She and Richard Axel identified over 1,000 olfactory receptors in mice, revealing how these receptors detect odors. Buck later uncovered the complex system behind odor perception, where multiple receptors detect one odorant, forming a combinatorial code. Her research extended to understanding how the brain processes odor signals, illuminating the profound effects of smell on memory and emotion. Linda Buck won a Nobel Prize in physiology for for discovering hundreds of receptors for odors in the nose and uncovering how information from those receptors is organized in the nose and then the brain.
Buck was really interested in how our sense of smell works. Her discoveries could help people who can't taste or smell, but Buck's main goal is just understanding how we sense and react to the world.

Sources (2):

https://www.nobelprize.org/womenwhochangedscience/stories/linda-buck

https://www.fredhutch.org/en/faculty-lab-directory/buck-linda.html#:~:text=Linda%20Buck%20studies%20the%20sense,nose%20and%20then%20the%20brain.

Contemporary - Potential of a Bioelectronic Nose

smith15517 — 2024-02-16 20:40:48 UTC

This artifact is from the study cited below. I chose this to depict how the bioelectronic nose is implanted and to give the reader an idea of what the study actually looked like with a graphic of how it works on the cellular level. This study focused on the detection and classification of natural odors using an innovative in vivo bioelectronic nose. Their approach integrates biological olfactory receptors with a field-effect transistor (FET) sensor array to create a sensitive and selective odor detection system. By genetically engineering and expressing olfactory receptors in human embryonic kidney cells, the authors effectively mimic the human olfactory system's ability to recognize odors. The FET sensor array detects changes in electrical signals when exposed to different odorants, enabling the discrimination of various natural odors such as coffee, garlic, and mint. This study demonstrates how the bioelectronic nose can be useful in different areas like making sure food is good, checking the environment, and diagnosing illnesses. It shows that this technology has a lot of potential and could lead to more improvements in how we detect smells in the future.

Sources (1):

Zhuang L, Guo T, Cao D, Ling L, Su K, Hu N, Wang P. Detection and classification of natural odors with an in vivo bioelectronic nose. Biosens Bioelectron. 2015 May 15;67:694-9. doi: 10.1016/j.bios.2014.09.102. Epub 2014 Oct 28. PMID: 25459058.

Poor Human Olfaction MYTH

smith15517 — 2024-02-16 20:41:09 UTC

This artifact is a figure from the article cited below. It is comparing the size of the olfactory bulb of a human (depicted on the right) versus the olfactory bulb of a mouse (depicted on the left). This artifact is important because throughout history there has been a misconception that humans have a poor sense of smell in comparison to other mammals. The origin of this is all based off of a 19th-century anatomist's hypothesis, proposing that as humans evolved to have more freedom of choice, their smell sense got smaller. Although this is an interesting idea, it was only a hypothesis - when in actuality, the human olfactory bulb is relatively large in absolute terms and contains a similar number of neurons as other mammals. In fact, we (humans) possess excellent olfactory abilities, being capable of detecting and discriminating a wide range of odors. We can also be even more sensitive to certain odors than other mammals, like rodents and dogs.

Sources (1):

McGann JP. Poor human olfaction is a 19th-century myth. Science. 2017 May 12;356(6338):eaam7263. doi: 10.1126/science.aam7263. PMID: 28495701; PMCID: PMC5512720.

Development of Human Olfactory Bulb

smith15517 — 2024-02-16 20:41:54 UTC

This artifact is a photo taken from the chapter cited below. They are MRI scans of 4 different individuals: A being a 4 month year old boy, B is a close-up of the first one, showing the cribriform plate (where smell nerves pass) and the area between the two brain hemispheres (marked with arrowheads), C is of a 9 year old boy with no olfactory bulbs, and D is of a 5 year old girl - on one side of her brain, the olfactory bulb and groove are there (marked with arrows), but on the other side, they're missing. It's important to see different cases and individual differences between patients and how smell testing is important because there is potential for disorders. This chapter discusses how the human sense of smell develops. Even before a baby is born, around 28-30 weeks into pregnancy, they can detect smells in the amniotic fluid. The olfactory bulbs, which are important for smelling, start forming around this time and can be seen on MRI scans. Sometimes, there may be issues with the development of these bulbs, both before and after birth. Olfactory nerves start connecting to the brain before the bulbs are fully formed, and there are specific areas in the brain that handle smell signals, similar to how other senses work. Even though smell doesn't go through the thalamus like other senses, the olfactory system still has structures that serve similar functions. The olfactory system continues to develop after birth, and abnormalities in the olfactory bulbs can be detected through various tests. The chapter suggests that testing a newborn's sense of smell could be useful, especially in babies with certain brain or genetic disorders, or those who had problems during birth.

Sources (1):

https://www.sciencedirect.com/science/article/pii/B9780444638557000034#:~:text=Olfactory%20perception%20in%20the%20human,bulb%20(Humphrey%2C%201940).

Understanding Olfaction in Humans

smith15517 — 2024-02-16 20:42:29 UTC

This artifact shows the 17 genes families that olfactory receptors belong to, it is depicted in the article cited below. This article discusses how olfaction is crucial for detecting and distinguishing odors as well as social cues that influence our natural reactions. Human sense of smell is remarkably precise, capable of detecting and distinguishing millions of different odor molecules even in tiny amounts. This process begins with odor molecules binding to specialized olfactory receptors, which are encoded by a large family of genes called Olfactory Receptor (OR) genes. When these receptors are stimulated, they convert the chemical information from the odorants into electrical signals, triggering responses in olfactory sensory neurons. The olfactory bulb then relays these signals to various parts of the brain for further processing. Odors are identified using a combination of receptors to detect different chemicals and encode their unique identities. The discovery of functional OR genes and proteins has provided valuable insights into the genetic, structural, and functional basis of olfaction. Olfactory receptors belong to 17 gene families, with some families containing over a hundred members each. Besides G-protein-coupled receptors (GPCRs), other types of receptors are also involved in detecting chemosensory stimuli. The article talks about how smell works, including the equipment involved, how information is transmitted, different ideas about how we perceive smells, and the problems researchers face. It also looks at recent studies about how smell works, both physically and in our brains.

Sources (1):

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7052838/#:~:text=Olfaction%2C%20the%20sense%20of%20smell,seems%20to%20be%20very%20precise.

Importance of Olfactory System in Human Wellbeing

smith15517 — 2024-02-16 20:43:35 UTC

This artifact depicts the important roles of the olfactory system in terms of human wellbeing. The artifact is taken from the article cited below. It shows the roles in terms of nutrition, social behavior, and protection. This article discusses how the olfactory system is truly undervalued, despite it playing a large role in the wellbeing of human beings. In regards to social behavior, smell contributes to emotional regulation. Emotional regulation is very important in everyday life, while also having a significant impact on social relationships throughout various life stages. Different life stages include: prenatal, postnatal, puberty, partner selection, and during sickness. The argument about the importance of the olfactory system stems from what results from the olfactory system. It is rooted in the idea that aspects of an individual's life, like social relationships and emotional states, are vital to an individual's wellbeing and the olfactory system plays a major role in those specific aspects - further playing a large role in the wellbeing of an individual.

Sources (1):

Boesveldt S, Parma V. The importance of the olfactory system in human well-being, through nutrition and social behavior. Cell Tissue Res. 2021 Jan;383(1):559-567. doi: 10.1007/s00441-020-03367-7. Epub 2021 Jan 12. PMID: 33433688; PMCID: PMC7802608.

Understanding Structure of Olfactory System

smith15517 — 2024-02-16 20:44:36 UTC

This artifact is a video explaining the structure and function of Olfaction. It explains how our sense of smell works and its importance in our ability to taste flavors. It describes the anatomy of the olfactory system, including the olfactory epithelium, cribriform plate, and olfactory bulb, and how molecules bind to receptors in the nose, triggering a cascade of events that ultimately result in the perception of odor in the brain. The process involves specialized cells in the olfactory epithelium, known as olfactory sensory cells, which detect specific odor molecules and send signals to the olfactory bulb, where they are processed and transmitted to the brain for perception.

Sources (1):

https://www.khanacademy.org/science/health-and-medicine/nervous-system-and-sensory-infor/taste-gustation-and-smell-olfaction-topic/v/olfaction-structure-and-function

Olfaction: Human v. Animals

smith15517 — 2024-02-16 20:45:59 UTC

This artifact is Figure 32.9 from the article cited below. It summarizes all comparisons of olfactory detection thresholds between human subjects and other mammal species. Depicted are the number of odorants for which either human subjects or a given species of mammal are more sensitive. With the exception of the dog (and the harbor seal, which has been tested with only one odorant), human subjects have lower olfactory detection thresholds, that is, a higher sensitivity with the majority of odorants tested so far compared to all other mammal species tested so far. This includes species traditionally considered to have a highly developed sense of smell, such as mice, rats, hedgehogs, shrews, pigs, and rabbits.

Sources (1):

https://link.springer.com/chapter/10.1007/978-3-319-26932-0_32#:~:text=With%20the%20exception%20of%20the,mammal%20species%20tested%20so%20far.

Memory and Olfaction

smith15517 — 2024-02-16 20:47:18 UTC

For this artifact, I chose the cover of the book this chapter cited below comes from. The chapter (15) explores the unique ability of odors to evoke vivid emotional experiences in humans, emphasizing the role of direct connections between the olfactory system and brain structures involved in emotion and memory, such as the amygdala and hippocampus. In animals, memory for environmental odors is crucial for survival and is often associated with significant life events. The chapter shows the aspects of the neurobiology of odor emotional memory in rats, both in infancy and adulthood, focusing particularly on fear conditioning as a model to study emotional memory. They chose to do this because the majority of studies investigating the neural basis of fear conditioning have focused on auditory and visual cues as conditioned stimuli, with well-characterized pathways involved in auditory fear conditioning. These pathways involve information traveling either directly from the thalamus to the amygdala or through the auditory cortex before reaching the amygdala. The paper further reviews the neural circuits involved in odor fear conditioning in adult rats and discusses the ontogeny of odor fear conditioning. One key argument presented in this chapter is that a single experimental approach can activate similar yet separate neural circuits and produce varying behavioral responses based on the age at which the learning occurs, demonstrating how the fear system can adapt to different life stages.

Sources (1):

Mouly AM, Sullivan R. Memory and Plasticity in the Olfactory System: From Infancy to Adulthood. In: Menini A, editor. The Neurobiology of Olfaction. Boca Raton (FL): CRC Press/Taylor & Francis; 2010. Chapter 15. Available from: https://www.ncbi.nlm.nih.gov/books/NBK55967/

Olfactory and Perception in Children

smith15517 — 2024-02-16 20:47:55 UTC

The paper cited below talks about how smelling things is important for kids, both for staying safe and enjoying life. It says that while it's rare for kids to lose their sense of smell, if they do, it could mean they have certain health issues. The paper explains how doctors test how well kids can smell, mostly by asking them to identify different smells. It introduces a new tool called the Pediatric Smell Wheel that helps test even very young kids' sense of smell. This artifact above is a photo of the Pediatric Smell Wheel. It suggests that kids as young as 4 can be tested, and their smelling skills get better as they get older. For example, older participants, like college-aged individuals, did much better than younger kids aged 4-5, 6-7, and 10-11. Also, 6-7 year olds and 10-11 year olds did better than 4-5 year olds, and 10-11 year olds performed better than 6-7 year olds. Interestingly, the scores of 6-7 year olds who took the test on their own were the same as those who were given the test by an examiner. Finally, it suggests other ways to test kids' smelling abilities to learn more about how they smell things.

Sources (1):

Cameron EL. Olfactory perception in children. World J Otorhinolaryngol Head Neck Surg. 2018 Mar 21;4(1):57-66. doi: 10.1016/j.wjorl.2018.02.002. PMID: 30035263; PMCID: PMC6051253.

Sleep and Smell

smith15517 — 2024-02-16 20:48:30 UTC

This artifact is a diagram cited in the source below. It depicts the relationship between olfaction and sleep. This article discusses how even though our sense of smell is quite different from how other senses work, it still gets affected by whether we're awake or asleep. When we're asleep, our ability to smell changes, and sleep is important for remembering smells. But interestingly, smells can also affect how well we sleep. Some scents might help us fall asleep faster or improve the quality of our sleep. This interaction between smell and sleep offers new ways to understand memory and perception, and it could lead to natural treatments for sleep problems that don't involve medicine.

Sources (1):

Gaeta G, Wilson DA. Reciprocal relationships between sleep and smell. Front Neural Circuits. 2022 Dec 22;16:1076354. doi: 10.3389/fncir.2022.1076354. PMID: 36619661; PMCID: PMC9813672.

Smell discrimination and Anosmia

smith15517 — 2024-02-16 20:49:46 UTC

This artifact is taken from the article cited below, it shows the when subjects are presented with seven common odors, the vast majority of “normal” individuals can identify all seven odors correctly, but these results from "normal" individuals differ greatly to those affected by Anosmia. In humans, the sense of smell is generally considered less acute compared to other animals. This is because many animals have more smell receptors in their noses and larger brain areas dedicated to smell. Despite this, humans are still good at detecting and identifying smells in the environment. For example, we can detect the aroma of bell peppers even at very low concentrations. However, the ability to detect smells varies greatly depending on the odor and its concentration. Some molecules can be identified at extremely low concentrations, while others need a much higher concentration to be recognized. Scientists have tried to classify odors into groups based on their perceived qualities and molecular structures. One popular classification system, developed by John Amoore in the 1950s, categorizes odors into groups like pungent, floral, musky, earthy, and others. Despite attempts to classify them, the perception of odors can be complicated. For example, the same molecule might smell floral at low concentrations but putrid at higher concentrations. Humans can usually identify a wide range of common odors, but some people have difficulty identifying certain smells, a condition called anosmia. Anosmia can be specific to one odor or more general. It's often caused by a missing olfactory receptor type. Aging can also affect our ability to identify odors, with older individuals typically able to identify fewer odors than younger ones. Severe loss of smell can be associated with various health conditions, including Alzheimer's disease, and can impact the enjoyment of food and the ability to detect dangerous odors like smoke or gas leaks.

Sources (1):

Purves D, Augustine GJ, Fitzpatrick D, et al., editors. Neuroscience. 2nd edition. Sunderland (MA): Sinauer Associates; 2001. Olfactory Perception in Humans. Available from: https://www.ncbi.nlm.nih.gov/books/NBK11032/