The potential and electric field in the cochlear outer hair cell membrane

Abstract

Outer hair cell electromechanics, critically important to mammalian active hearing, is driven by the cell membrane potential. The membrane protein prestin is a crucial component of the active outer hair cell’s motor. The focus of the paper is the analysis of the local membrane potential and electric field resulting from the interaction of electric charges involved. Here the relevant charges are the ions inside and outside the cell, lipid bilayer charges, and prestin-associated charges (mobile-transferred by the protein under the action of the applied field and stationary-relatively unmoved by the field). The electric potentials across and along the membrane are computed for the case of an applied DC-field. The local amplitudes and phases of the potential under different frequencies are analyzed for the case of a DC+AC-field. We found that the effect of the system of charges alters the electric potential and internal field, which deviate significantly from their traditional linear and constant distributions. Under DC+AC conditions, the strong frequency dependence of the prestin mobile charge has a relatively small effect on the amplitude and phase of the resulting potential. The obtained results can help in a better understanding and experimental verification of the mechanism of prestin performance.

Protein structural transition at negatively charged electrode surfaces. Effects of temperature and current density

“…It is not excluded that conformational changes of biomacromolecules interacting in cells with various charged surfaces might be facilitated by electric field effects, making studies of conformational changes in surface-attached proteins even more interesting. Numerous investigations suggesting electric field effects on protein and cell systems even at nanosecond time intervals support this assumption [26][27][28][29][30][31].…”

Emerging Roles of the Membrane Potential: Action Beyond the Action Potential

“…The electromechanics of the cochlea are driven by the hair cell RMP (reviewed by Ashmore, 2008 ). The cochlea outer hair cells play a key role in sound amplification and fine frequency selectivity that works via two interrelated mechanisms: somatic electromotility ( Brownell, 2017 ) and the active hair bundle ( Harland et al, 2015 ). The cochlea of the mammalian inner ear is filled with two different extracellular solutions, the perilymph and endolymph, separated from each other by hair cells.…”

Electromechanics of polarized lipid bilayers

“…The creation of nanopores in lipid membranes by external electric fields is a standard technique -known as electroporation -to deliver genes into cells [Neumann et al 1982;Aihara and Miyazaki 1998;Weaver 2000] and in some cancer treatments [Davalos et al 2005;Rubinsky et al 2007]. The role of coupled electromechanical interactions is well recognized in the context of cochlear outer hair cells [Brownell et al 1985;Raphael et al 2000;Harland et al 2015]. Electromechanical interactions also play a fundamental role in electrically active cells such as neurons.…”