The Salty and Burning Taste of Capsaicin

The tongue is a kind of funny organ. From a physiological point of view, you can place solutions on the tongue that will be toxic to most any cell, and the tongue will give information, in a hopefully reversible manner, about the solution's chemical composition and whether it should be ingested. Remember the first time that you had a drink of vodka or scotch? It really burned. Do you know the reason for this? It turns out that neurons in the mouth, including the tongue, that carry nociceptive (tissue damaging) information contain receptors belonging to the transient receptor potential vanilloid (TRPV) family. The most investigated of these TRPV receptors is TRPV1. One reason TRPV1 is so extensively studied is that it is activated by capsaicin (CAP), the principle component in chili pepper that gives it its spicy or pungent taste (Caterina et al., 1997...