MadSci Network: Neuroscience |
Aloha, Emily Thank you for submitting such an interesting question. In fact, I had to go back to several of my anatomy/physiology texts to be sure of the answer. That means I was able to learn something, too. According to one of the current college-level textbooks (_Fundamentals of Anatomy and Physiology_ by Frederic Martini, 3rd. edition), tastebuds do differ in their sensitivity to stimuli. In general, the tastebuds that respond to 'bad' tastes (bitter and sour) do so at a much lower level of substances than do the tastebuds that respond to 'good tastes' (sweet and salty). This makes sense evolutionarily, since we would have wanted to avoid the bad tasting-stuff (sometimes dangerous, too) and take in the good-tasting stuff (probably for the energy and nutrients). For example, compounds called acids (which taste sour) can damage the cells that make up the lining of the mouth...and many bitter substances are also toxic, or poisonous, to the human. Also, did you know that each person has a slightly different sensitivity to tastes? These differences are probably inherited from your biological parents. Some people are extremely sensitive to a chemical called 'phenylthiourea'....some people can't taste it at all. Lastly, your ability to taste will change with age. By the time you are about 50 years old, you may begin to lose lots of your ability to taste. If you have anyone in your family around this age, they may talk about how bland their food tastes. That same food may taste very salty, spicy, or sweet to you now. This could be an interesting experiment for you to try, don't you think? Thanks again for such an interesting question. Dian Dooley
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