A model of ionic transport and osmotic volume control in cochlear outer hair cells

Abstract

A computational model of the outer hair cell (OHC) of the mammalian cochlea is presented. It addresses the way in which movement of ions controls the cell shape and regulates pH. The model takes into account the possible chloride-bicarbonate exchange function of prestin, a protein highly expressed in the plasma membrane of OHCs. A model of intracellular pH transients following the imposition of a rapid acid load upon the cell has been adapted from the squid axon literature and further extended in order to investigate the effects of ion transport upon the osmotic flux ofwater into the cell. The model predicts the slowlength changes ofOHCs reported in the literature a featurewhichmay control the contribution of OHCs to cochlear amplification.