Electroanatomy of the lateral wall of the cochlea.

Metabolically, the most active membrane in the stria vascularis is the marginal cell membrane adjacent to the intermediate cells. It is probably at this site that K+ions are actively transported in and Cl minus ions are actively transported out by the Na+ in equilibrium K+, K+in equilibrium H+, and Cl minus ion pumps. Support for this hypothesis was derived from the work of other authors, from our own earlier results and the experimental results presented in this paper. Our experiments indicate that the marginal cells of the stria vascularis facing the endolymphatic space have a positive intracellular potential similar to the potential of the scala media, Therefore, the major portion of the active ion transport takes place on the intermediate cell side of the marginal cells. The pumping mechanisms, localized in this membrane, are responsible for the generation of the positive endocochlear potential (EP).