[Functional relationships between the horizontal and vertical anterior semicircular canals in the labyrinth of the frog (Rana esculenta L.)].

We have studied the vestibular postrotatory reactions (reactions elicited by the stimulation of the horizontal semicircular canals) in the frog blinded by section of optic nerves, before and after section of the ampullary nerves of the vertical anterior semicircular canals (VAC). 90 frogs have been studied. In 30 frogs the ampullary nerves of the two VAC have been cut; in 60 animals either the ampullary nerve of the right VAC or of the left VAC has been cut. Both after section of the ampullary nerves of the two VAC and after section of the ampullary nerve of one VAC, the postrotatory reactions were decreased in about the half of the animals. The decrease of the postrotatory reactions is not due to a lesion of the ampullary nerves of the horizontal semicircular canals and it may be explained by the existence of functional connections between the VAC and the horizontal canal.