ADAPTATION OF THE FROG TONGUE TO BITTER SOLUTIONS - ENHANCING EFFECT ON GUSTATORY NEURAL RESPONSE TO SALT STIMULI

1. 1. The initial phasic component of frog gustatory neural responses to various 0.1 M salt solutions was greatly augmented in amplitude after the tongue was adapted for 10 sec to 1 mM quinine-HC1 (Q-HCl), quinine-H2SO4 (Q-H2SO4) and picric acid. 2. 2. Out of 103 examined gustatory units responding to both 0.5 M NaCl and 1 mM Q-HCl or to 0.5 M NaCl alone, 67% exhibited an enhancement of response to the NaCl after the Q-HCl adaptation but the remaining 33% showed a suppression or no alteration of NaCl response after the Q-HCl. 3. 3. Intracellular taste cell responses to salt stimuli after 1 mM Q-HCl adaptation showed an initial phasic depolarization which was not observed under control Ringer adaptation. This de polarization might be concerned with the enhancement of initial phasic neural responses to salts following the Q-HCl adaptation. © 1979.