Morphology of cochlear inner hair cells following outer hair cell destruction by kanamycin intoxication in the chinchilla

Abstract

Inner hair cells were examined in cochlear regions of outer hair cell destruction caused by kanamycin intoxication. The majority of inner hair cells were ultrastructurally normal, except that some exhibited a slight increase in inclusion bodies in the region between the cell nucleus and the cuticular plate. Only in the extreme cochlear base, where kanamycin damage was maximal, were major changes in inner hair cell morphology seen: while many inner hair cells were normal in appearance, others showed extrusion of the cuticular plate from the reticular lamina, fusion and/or encapsulation of stereocilia, or distortion of cell body shape. Such damage appeared secondary to changes in structural cells of the organ of Corti.