Actin distribution along the lateral wall of gerbil outer hair cells.

Outer hair cells can contract parallel to their long axis, and it has been hypothesized that actin may play a role in this contraction. In this study, actin distribution was examined in the gerbil organ of Corti using postembedment immunoelectron microscopy. In addition to regions typically labelled by actin antibodies and observed by epifluorescence--the cuticular plate, stereocilia, and supporting cell processes--these procedures preserved the ultrastructure of the cell and allowed us to demonstrate actin reactivity along the lateral wall of the outer hair cells between the subsurface cisterns and the plasma membrane. This region is the location of structures (pillars and cortical cytoskeleton) though to be associated with contraction of the outer hair cells.