Loss of sensitivity to low concentrations of NaCl following bilateral chorda tympani nerve sections in rats.

A reliable short-term NaCl taste test was developed for rats which resulted in differential responding to a variety of concentrations. The rats were required to exist on a low sodium diet for 8-10 days prior to the initiation of testing. The peak response in this test was to isotonic NaCl with lesser responding to hyper- and hypotonic solutions. After stable responding was obtained, bilateral sections were made of the chorda tympani nerves. This surgery resulted in a loss of sensitivity to the lowest hypotonic solutions (0.03 and 0.06 M NaCl). Little, if any, effect was noted in the perception of sucrose following these nerve sections.