How many times have you been asked to “map” your tongue? Did you (or your students) use solutions and cotton swabs to generate that classic map of sweet, salty, bitter, sour and, now, savory (umami)? We know now that the map is artificial. But what happens when the molecules found in food hit the taste buds?
Research from the University of Pennsylvania suggests that when you eat something sweet, bitter or savory (umami), your taste buds release ATP as a neurotransmitter to trigger neurons to carry the message to the brain’s taste centers. However, when you eat something sour or salty the signal to the brain seems to work by a different biological mechanism. This new research helps us trace the path from food to taste bud to receptor to transmitter release to nerve impulse to brain. So…in my unending quest to have yet another reason to eat chocolate, I wonder…if we eat sweet foods, does the ATP release significantly counterbalance the intake of calories? (OK, that one is just wishful thinking!).
Lovelace found that people vary in the number of taste buds per square millimeter of tongue surface and in their taste sensitivity. In one study, she found that people who cook for a living (e.g., chefs) had greater taste sensitivity than did people in other professions. Those with proportionately more taste buds have been labeled “supertasters.” Want to know where you stand on the taste bud density issue? A drop of blue food coloring on your tongue will let you see your taste buds, should you be into quantification! Hmm…do supertasters use up significantly different amounts of ATP when eating sweet, bitter, or savory foods compared to normal tasters? Something to think about. Or perhaps something just to savor the next time you pop a Hershey kiss.
Want to try out some taste and other sensory activities in your classroom? Check out the LifeSciTRC resource Welcome to Your Senses.
Marsha Matyas, PhD is a biologist, educator, and science education researcher. For nearly 30 years, she has worked at scientific professional associations (AAAS and now APS) to promote excellence in science education at all levels and to increase diversity within the scientific community. Her research focuses on factors that promote science career interest and success, especially among women and underrepresented minorities. She directs the Education Office and programs at APS, which span from pre-Kindergarten to professional development and continuing education for Ph.D. and M.D. scientists. In her free time, Marsha enjoys traveling with her family and scrapbooking.