Physicochemical studies of taste reception. V. Suppressive effect of salts on sugar response of the frog

The model membrane composed of a Millipore filter paper and the total lipids from bovine tongue epithelium or phosphatidylcholine from egg yolk simulated well the water response of a living taste cell. The water response observed with the model membrane adapted to various salt solutions was interpreted in terms of changes in electric potential at the membrane-solution interface, i.e. the water response was attributed to the e.m.f. change produced by diffusion of the electrolytes dissolved in (or adsorbed on) the membrane surface into the bulk solution.The water response of the frog tongue was also investigated by measuring the neural response of the glossopharyngeal nerve. The results obtained were consistent with the mechanism proposed in the present paper. The response of the frog to Ca²⁺ was examined under the condition where the water response was suppressed, and it was concluded that the water response of the frog is different from the response to Ca²⁺.