The Lateral Walls of Inner and Outer Hair Cells

Abstract

Outer hair cells (OHCs) are thought to play a role in influencing cochlear micromechanics and have been shown to be actively motile; inner hair cells (IHCs) are presumed to be mechanically passive receptor cells and there is no evidence that they are able to contract. A detailed examination of the structural differences and similarities between IHCs and OHCs may provide clues as to particular specialisations of OHCs which are relevant to cochlear micromechanics. Some evidence has suggested that such specialisation is associated with the lateral wall of the OHC (i.e. the lateral plasma membrane and underlying lateral cisternae) (Flock et al., 1986; Holley and Ashmore, 1988). In the work to be presented here, thin sections, freeze-fracture and freeze-etching have been used to to examine the lateral walls of IHCs and OHCs in the intact organ of Corti of the guinea pig, the the gerbil and the mouse. Some preliminary data on freeze-fractured isolated OHCs of the guinea pig is also presented.