Responses from Isolated Individual Semicircular Canal Ampullae in Frog

Abstract

By using isolated semicircular canals of frogs and a stimulator which induced a current of fluid within the ampulla the author proved the correctness of Ewald's law on the basis of the response from the ampullar nerve. Namely, in the anterior and posterior canals an ampullofugal current showed a stimulating effect, while in the lateral canal an ampullopetal current provoked an increase in the nerve discharge. On alternate ampullofugal and ampullopetal currents given from the site of the utricular duct through the lateral and anterior canals, an alternating increase in the nerve discharge was observed, as the form of receptor function is opposite in these canals. The present method is believed to be a unique way to study Ewald's law.