Hairs of the Cochlear Sensory Cells and Their Attachment to the Tectorial Membrane

Abstract

The hairs of the sensory cells in the cochleae were studied with emphasis on their attachment to the tectorial membrane. So far we have observed that the peripheral row of tall hairs of the W form and a few inner rows at its base were shallowly but firmly embedded in the tectorial membrane. The hair tops were more electron dense and delimited from the tectorial membrane by the unit membrane of the sensory cell. The hairs of the inner sensory cells were likewise arranged in a W form with the tallest hairs in the peripheral row. Modified cilia and numerous short hairs or microvilli were demonstrated at the base of the W in the sensory cells of the undifferentiated organ of Corti, but were lacking in the specimens of older animals. This work was supported by U.S. Public Health Grant NB 03932-03. Der Verfasscr untersuchte die Haare tier akustisclien Sinneszellen und widmete besondere Aufmerksamkeit ihrer Beziehung zur Membrana tectoria. Die Reihe der peripheren hohen Haare, die einen W-förmigen Saum bilden, sowie einige innere Reihen von Haaren waren an der Basis flach aber fest in die Membrana tectoria eingebettet. Die Spitzenpartie der Haare war elektronenoptisch dunkler und wurde durch cine Grenzmembran der Sinneszelle von der Membrana tectoria getrennt. Die Haare der inneren Sinneszellen bilden ebenfalls eine W-förmige Reihe, wobci die höchsten Haare periphcr stehen. Im Entwicklungs-stadium wurden Cilien an der Basis des W angetroffen, jedoch fehlten diese im entwickclten Cortischen Organ.