Functional and morphological response of the stria vascularis following a sensorineural hearing loss

Abstract

Cochlear endolymph is maintained at a potential of (+)80 mV by an active transport mechanism involving the stria vascularis (SV). This so-called endocochlear potential (EP) is integral to hair cell transduction. We compared the EP with changes in SV area and Na(+),K(+)-ATPase expression following a sensorineural hearing loss. Guinea pigs were deafened using kanamycin and a loop diuretic, and the EP was measured at two, 14, 56, 112 or 224 days following deafening. Auditory brainstem responses were used to confirm that each animal had a severe-profound hearing loss. There was a significant reduction in EP following two days of deafness (normal, 73.5 mV S.E.M.=2.4; deaf, 42.1 mV, S.E.M.=2.8; P<..