Nonlinear electroelastic model for the composite outer hair cell wall.

A nonlinear electroelastic model for the composite wall of the cochlear outer hair cell is proposed. The cell wall is modeled as a two-layer shell with elastic connections between the layers: an active layer corresponds to the plasma membrane and a passive layer corresponds to a combination of the cytoskeleton and the subsurface cisternae. As a basis of the constitutive relations, a thermodynamic potential for such a composite wall is developed. Expressions for the components of the active force are obtained in terms of the active strains and the elastic properties of the passive and active layers. An application to the electrical stimulation of the cell under the conditions of the microchamber experiment is given. As a result, active strains, active forces, and mechanical energy stored in each of the two layers are presented as functions of the wall (membrane) potential.