An electrophysiological study of taste reception in peripheral nerves of the calf

Abstract

Multiunit neural activity was recorded from gustatory nerves of 28 calves following chemical and mechanical stimulation of the tongue. The chorda tympani nerve was found to have a posterior, in addition to the classical anterior, receptive field. The anterior field responded to NaCl and acetic acid, starting at 0.001 m, and KCl and propionic acid, starting at 0.01 m. Fructose, glucose, xylose, and sucrose had higher thresholds and were less effective than equimolar concentrations of the salts and acids studied. Quinine sulfate, Na saccharin, distilled H₂O, and mechanical stimulation produced small responses. In contrast, the posterior field yielded large responses to distilled H₂O and to mechanical stimulation. Many of the same chemical stimuli were effective, but had different response characteristics. In relation to NaCl, acetic acid was more effective on the posterior than the anterior field. On the receptive field of the glossopharyngeal nerve mechanical stimulation was more effective than chemical stimulation, which produced small responses from high stimulus concentrations. The behavioral taste responses of bovines are compared with the electrophysiological data.