Changes in physiological properties of frog taste cells following denervation

The structure of the taste organ and the physiological propertiesof the taste cell of the bullfrog (Rana catesbeiana) after theglossopharyngeal nerve transection were investigated. The frogtaste organ is composed of taste, supporting and basal cells.As nerve terminals within the taste organ degenerated, nerveresponses to mechanical, chemical and electrical stimuli graduallydeclined and finally ceased in 7 days during the summer and15 days during the winter. However, the taste cells still hadresting potentials and responded to four basic taste stimuliby generating receptor potentials with the various lengths ofduration, even 140 days after denervation. The glossopharyngealnerve transection affected the magnitude of resting potentialssignificantly. However, the taste, supporting and basal cellsmaintained their normal structures 140 days after surgery. Itis concluded, therefore, that neural dependency of the frogtaste organ is not as great as that in mammals.