Relationship of the Tectorial Membrane to the Organ of Corti.

Abstract

The connections between the tectorial membrane and the organ of Corti in the cat and guinea pig were studied by scanning electron microscopy. Postnatal development of the organ of Corti is extensive during the first month after birth. Therefore, young kittens from 1 to 32-day-old as well as adult animals were examined. The outer margin of the tectorial membrane was attached to the 3rd row of Deiters' cells in young animals. This attachment started to deteriorate around the 20th postnatal day. No marginal connections were found in adult animals. In the adult animals, there was a shallow insertion of the tips of the longest hairs of the outer hair cells into the undersurface of the tectorial membrane. With the exception of a 10-day-old cat specimen, the inner hair cell hairs were not inserted into the tectorial membrane and, instead of a direct connection, the inner hair cell region appeared to be loosely connected to the tectorial membrane by fibrous strands. In a 10-day-old cat, the under-surface of the tectorial membrane showed imprints which indicated the insertion and possible attachment of the inner sensory hair tips to the membrane.