ANALYSIS OF CHORDA TYMPANI RESPONSE FOR CHEMICAL STIMULATION TO RAT TONGUE UTILIZING NEW SUMMATOR

Abstract

The afferent impulses were recorded from the chorda tympani appling the taste stimuli to the rat tongue, as summated response by new summator with high accuracy instead of the integrator. The impulses/0.1 sec to the Na com-pounds (NaCl, HCOONa, CH3COONa, C2H5COONa and (CHOH)2(COONa)2) increased with their concentration (0.1-1.0 M) and decreased with the lengthening of the anion chain in case of monovalents, but not in divalent. Below 0.5 M solutions of K compounds (KCl, CH3COOK, C2H5COOK), similar results were obtained but the number of impulses was less than with Na compounds. The relations of C/ I-C were linear (I=the total number of impulses for 1, 2, and 3 sec, C=the concentration of Na compounds), but the equilibrium constant (K) was not peculiar to the chemical substances. The same linear relation as above was observed only in case of KCl (below 0.5 M). The responses to 0.5 M NaCl, KCl, CaCl2, and 0.1 M quinine HCl were analyzed statistically, a specific temporal pattern was found for each chemical substance. Based on the experimental results, the stimulating mechanism of chemical substances to taste receptor was discussed.