Morphological changes of hair cell stereocilia and tectorial membrane in guinea pigs with experimentally induced hydrops.

Endolymphatic hydrops was surgically induced in guinea pigs. Atrophy of middle and short stereocilia on the outer hair cells in the upper 13 mm of the cochlea was systematically observed by scanning electron microscopy in guinea pigs with hydrops between 5-22 months. Light microscope and scanning electron microscope observations indicated that the tectorial membrane in the apical three turns was often abnormally elevated, and could be vertically positioned in longstanding hydrops. The atrophy of outer hair cell middle and short stereocilia and the elevation of the tectorial membrane certainly contribute to the pathophysiology of experimental hydrops and might be implicated in Menière's disease.