Effect of Anoxia on Cochlear Potentials

Abstract

The anterior inferior cerebellar artery of guinea pigs was occluded, thereby interrupting the blood supply to the cochlea. Durations of occlusion ranged from 1 through 60 min. Cochlear microphonics, summating potential, action potential, and endocochlear potential were recorded before, during, and subsequent to occlusion. The differential effect of anoxia on the various potentials was observed, as well as the appearance of the large negative dc potential in scala media as anoxia progressed. For the brief occlusion durations, the amplitudes of all potentials except cochlear microphonics became greater than normal soon after the blood supply returned. Even for the longer anoxic intervals, the summating potential and the endocochlear potential exhibited super-normality during the recovery process.