Response characteristics of three taste nerves in mice

Gustatory responses from 3 nerves, the chorda tympani, glossopharyngeal and superior laryngeal nerves were investigated in the mouse. Stimuli were NH4Cl, NaCl, KCl, HCl, quinine-HCl, sucrose, urea, glucose and distilled water. The 3 nerves responded differently to these stimuli. The chorda tympani responded strongly to HCl and sucrose, but weakly to quinine-HCl, while the glossopharyngeal responded well to quinine-HCl rather than to either HCl or sucrose. The order of effective stimulation was NH4Cl greater than NaCl greater than KCl for the chorda tympani, whereas NH4Cl greater than KCl greater than NaCl for the glossopharyngeal nerve. The responses of the superior laryngeal nerve were remarkably different from those of the others. Water was the most effective stimulus for the nerve and the response to water was depressed by either electrolytes or non-electrolytes added in water. These results suggest dissimilar contributions of the 3 nerves to the physiological functions.