28 November 2015

Sensation of Taste Is Built into Brain

Scientists from Columbia University have figured out how to turn tastes on and off in the brain using optogenetics, a technique that uses penetrating light and genetic manipulation to turn brain cells on and off. They reported their findings in an article published last week in Nature. By manipulating brain cells in mice this way, the scientists were able to evoke different tastes without the food chemicals actually being present on the mice’s tongues. The experiments re-conceptualize what we consider the sensory experience.
 

Results further demonstrate that the sense of taste is hardwired in our brains unlike our sense of smell, which is strongly linked to taste but almost entirely dependent on experience. Typically when we eat, the raised bumps, or papillae, that cover our tongues, pick up chemicals in foods and transmit tastes to the brain. There are five main types of papillae corresponding to each of the five basic tastes—sweet, sour, salty, bitter and umami. Contrary to popular belief, these aren’t clustered in particular places on the tongue, with bitter in the back and sweet at the front, but are spaced about evenly on the tongue.

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