Electrophysiological and behavioral studies on taste effectiveness of alcohols in rats

Electrophysiological and behavioral studies were performed in rats to analyze the gustatory effects of alcohols, such as methanol, ethanol, ethylene glycol, 1-propanol, 2-propanol, propylene glycol, 1,3-propandiol, and glycerin. When the whole bundle responses to each of the alcohols at 1.0 M were recorded from the chorda tympani (CT) and glossopharyngeal nerve (Gl), the alcohols with two or three hydroxyl groups elicited larger responses than the other alcohols in both nerves. Single-fiber analyses showed that the responses to alcohols were induced dominantly in sucrose-best fibers and were correlated well with sucrose responses in the CT, whereas the responses to alcohols were induced in quinine-best fibers and were correlated well with quinine responses in the Gl. The rats that acquired conditioned taste aversions to alcohols with two or three hydroxyl groups also avoided sucrose and quinine, although the aversion did not generalize to NaCl or HCl. These results suggest that alcohols have a taste similar to the taste of both sucrose and quinine in the rat.