Observation on the Organ of Corti with Scanning Electron Microscope

Abstract

With the scanning electron microscope, three-dimensional observations of the organ of Corti were carried out. Some of the remarkable findings are presented as follows.

1) The cuticular plates of the second and third row outer hair cells are octagonal, and on the periphery of the cuticular plates there are numerous microvilli.

2) The basal body of the first and second row outer hair cells is distinct but the one of the third row outer hair cells is not quite so distinct. Inner hair cells have no basal body, but some of them have a bump-like process at the site where the basal body is supposed to be.

3) Some hairs show the nodules.

4) Fibers of the laminal process of the outer pillar cells are seen reaching over the cuticular plates of the outer hair cells like climbing ivy.

5) The structures of the upper and lower surfaces of the tectorial membrane were observed in detail.

The most characteristic feature observed is the three-dimensional findings of the hollows arranged in V-shape on the lower surface of the tectorial membrane, to which the tips of hairs of the outer hair cells fit.