Scanning electron microscopic observation of the tectorial membrane in the guinea pig cochlea

Object To understand the function of the tectorial membrane in hearing process. Methods The ultrastructure of the tectorial membrane in the cochlea of guinea pigs was observed under the scanning electron microscope. Results The fibrous nets were found on the upper surface of tectorial membrane. A stripe of undersurface of the tectorial membrane corresponded to the position of the hair bundles of the inner hair cells. Normal imprints of stereocilia under the tectorial membrane of the guinea pigs were observed in the lower and upper basal cochlear turns by scanning electron microscope. In the lower surface of the tectorial membrane,there were impressions where tops of the hair bundles of the outer hair cells reached. The W-shaped arrangement of these outer hair cell′s stereocilia made the W-shaped imprint on the tectorial membrane. Conclusion Contact between the tectorial membrane and inner and outer sensory hairs cells was discussed from the scanning electron microscopic finding.