Effect of Cyanide on Cochlear Potentials

Abstract

Cochlear potentials were recorded before, during and after perfusion of the scala tympani or scala vestibuli with Ringer's solution containing 50 millimoles of sodium cyanide. Cochlear potentials, including endocochlear potential (EP), were promptly depressed by the action of cyanide and a negative potential was observed in the scala media. The intra-cellular resting potential within the organ of Corti was markedly decreased. Introduction of cyanide into the scala tympani was more effective than in the scala vestibuli. Spontaneous recovery of responses was observed in most of the cases. The application of anodal polarization to the cochlea enhanced cochlear microphonics (CM) which had been depressed by cyanide. These data indicate that the cochlear partition is permeable to cyanide and confirm the view that the negative potential in the anoxic scala media is essentially a depolarization potential of the hair cells in the organ of Corti.