Functional physiology of the semicircular canal ampulla.

Physiology of the semicircular canal (sc) was studied by applying different manipulations to the isolated frog sc. Function of the cupula was investigated by mapping out the mechanical sensitivity on the cupular surface and by removing and replacing the cupula. The cupula was found to be most essential for effective activation of sc receptors. Responses of sc receptors to direct temperature change were studied. The sc nerve discharge increased and decreased due to cool and warm temperature change respectively. This suggests a possibility of direct temperature effect as one of the mechanisms of caloric response.