Effects of isoproterenol treatment on gustatory neural responses in three inbred strains of mice.

1. Treatment of a beta-agonist, isoproterenol, for 5 days reduced chorda tympani responses to sucrose by about 40% of the control without affecting responses to other taste stimuli, such as NaCl, HCl and quinine HCl, in balb CrSlc mice whereas such reduction of sucrose responses was not observed in C57BL/6-CrSlc and C3H/HeSlc mice, although in the latter two strains long-lasting off-responses to quinine HCl appeared after the treatment. 2. In BALB mice, the magnitude of reduction of sucrose responses by isoproterenol increased with prolonging the treatment from 1 to 5 days, although it reached almost its maximum level by the 3 days treatment. 3. BALB mice with the removal of the submandibular glands showed slightly greater control responses of the chorda tympani nerve to sucrose than BALB mice with the sham-operation or the removal of the sublingual glands, and showed no significant reduction of sucrose responses by isoproterenol treatment. 4. These results suggest that isoproterenol probably did not act directly on sweetener receptors of taste cell membranes but affect them through the submandibular salivary system.