Smell and taste play essential roles in our daily lives. The chemical senses serve as important warning systems, alerting us to the presence of potentially harmful situations or substances, including gas leaks, smoke, and spoiled food. Flavors and fragrances are also important in determining what foods we eat and the commercial products we use.
The pleasures derived from eating are mainly based on the chemical senses. Thousands of Americans experience loss of smell or taste each year resulting from head trauma, sinus disease, normal aging and neurological disorders, such as brain injury, stroke and Alzheimer’s disease. By providing a better understanding of the function of chemosensory systems, scientific and biomedical research is leading to improvements in the diagnoses and treatment of smell and taste disorders.
Among those contributing to advancements are members of the Association for Chemoreception Sciences (AChemS), which will be holding its 29th annual meeting in Sarasota, FL, April 25-29, 2007. In Sarasota, scientists are presenting their latest research findings on topics ranging from molecular biology to the clinical diagnosis and treatment of smell and taste disorders. The 2007 meeting is featuring presentations of new research findings, special symposia, and workshops (see Program Summary) sponsored by AChemS, corporations, and the National Institutes of Health. On Wednesday, April 25th, at 10:00 A.M., AChemS members will present an educational outreach program for local elementary and high school students at the GWIZ Science Center.
Additionally, there will be nine, special-subject symposia and two workshops. Throughout the five-day meeting there will be over 500 research presentations by AChemS scientists from around the world (for details see Complete List of Abstracts).
Some new findings to be presented at the meeting (click title for additional information): Risky Brain Response: Brain Response in People at Risk for Alzheimer’s Disease – Alzheimer’s disease (AD) causes devastating effects on memory as the victim slowly deteriorates. We have studied people at risk for AD to identify early changes that may signal the beginning of AD. When trying to remember, people at risk showed different patterns of brain response than those without genetic risk.
The Brain Automatically Adjusts to Boost Nose?s Smelling Capability When Needed ? Data from various sensory systems in numerous species suggest fast oscillations in neural assemblies are a mechanism to facilitate stimulus representation. We show that gamma oscillatory power in the rat olfactory bulb is modulated by the rats online according to task demands. This enhancement reflects a strategy shift in the dynamics of the system.
If You Mix a Pleasant and Unpleasant Odor, What Do You Get? – When you mix 25% pleasant odor with 75% unpleasant odor, it becomes much less unpleasant than 100% unpleasant odor. This change, however, may be due more to the 25% reduction in unpleasant odor than to the addition of 25% pleasant odor. In this study we aim to elucidate the rules underlying this interaction such that we will be able to predict the pleasantness of odor mixtures based on the pleasantness of their components.
Smelly Environments Make Better Noses – Exposure to an odor for one hour per day for less than two weeks changes the brain and make rats better smellers. The improvement comes from increasing the number of responsive small inhibitory interneurons in the olfactory bulb, resulting in stronger cooperativity within the olfactory bulb when rats sniff odors.
Dousing the Flame on Your Tongue with Pharmacology – The spicy hot sensation from peppers is due to a chemical, capsaicin, which activates a receptor in your tongue. In studies using mice, Scientists at Redpoint Bio Corp have used antagonists of the receptor to abolish the aversive response to capsaicin. This is the first demonstration of an antagonist of taste receptors being used to eliminate an aversive taste.
Coffee or Candy? Lemon or Salt? Solving the Taste Representation Puzzle in the Brain – Discrimination between foods is crucial for the nutrition and survival of animals. How the information about taste stimuli is processed by the brain is still subject of large debate. We show for the first time that each modality is represented by specific regions in the gustatory cortex. These regions can be used by the brain to discriminate among taste stimuli.
Different People, Different Tastes: New Genetic Evidence – Genes control many aspects of our lives ? from the color of the eyes to susceptibility to diseases. We identified specific variants of two human genes involved in sensing bitterness of several molecules, including a common sweetener, saccharin. We show that whether people taste those molecules as bitter or not depends on which variants of these genes they have.
Mom?s Smell Helps Organize Your Day (If You?re a Baby Rabbit) – Most organisms show daily rhythms in a wide range of physiological and behavioral functions. These rhythms are typically controlled by the daily light/dark cycle. Using the rabbit, we show for the first time that pheromonal cues from the mother can perform the same function in still blind mammalian young.
How the Nose Tells Time – The richness of smells such as that of a good red wine seems to develop slowly over some seconds. We have visualized precisely timed and odor-specific patterns of neural activity in isolated mouse olfactory bulb neurons that may provide a mechanism for the slow changes in the perceived qualities of odors.
GABA, A Neurotransmitter Found in Taste Buds – Glutamate decarboxylase (GAD), an enzyme that produces gamma-amino butyric acid (GABA), is found in taste buds. The enzyme functions to produce GABA which may interact with GABA-specific receptors, including those in the chloride channel. The enzyme is expressed specifically at type III cells within the taste buds. Since type III cells are connected to the nerve cells, GABA may be a key participant in taste signal transduction.