Two-state model for outer hair cell stiffness and motility.

With discovery of the protein prestin and the gathering evidence linking it to outer hair cell electromotility, the working mechanism of outer hair cells is becoming clearer. Recent experiments have established the voltage-dependent stiffness of outer hair cells and given an insight into the nature of variation of stiffness with respect to voltage. These and earlier experiments are used to analyze and develop models of outer hair cell response. In this article, recent modeling efforts have been reconciled and placed into a common mechanics-based framework. The constitutive models are analyzed with regard to their capability to replicate experimental results. We extend the area motor model to include elastic constants dependent on motor state. The modified model successfully captures stiffness variations of outer hair cells and capacitance changes with respect to voltage.