Flockwave- Propagation Modes and Boundary Conditions for the Ulfendahl-Flockkhanna Preparation

Abstract

Let us consider, in a simplified way, the cross-section of one cochlear turn. If Outer Hair Cells (OHC’s) can exert forces, they can do this in essentially two ways. In the first way the cilia actively move the Tectorial Membrane (TM) and in doing so, set also the Basilar Membrane (BM) into motion. Because of the relatively small stiffness of the cilia (Strelioff and Flock, 1984) and, especially, the tectorial membrane (TM) (Zwislocki and Cefaratti, 1989) this would be unlikely. In the second way the Organ of Corti (DC) is deformed by the OHC’s, either by lengthening-shortening (Ashmore, 1987) or via tilting (Gitter and Zenner, 1988). On both Sides of the OC strictly local defonnations can occur (displacements over only a part of the width) as well as uniform or over-all deformations (displacements over the entire width). Elsewhere it has been shown that local deformations couple very weakly to the movements of the cochlear fluids (de Boer, 1990). Coupling with unifonn displacements will be the topic studied in the present paper.