The role of macrophages in the disposal of degeneration products within the organ of corti after acoustic overstimulation.

We analysed the ultrastructure of scavenger cells in the organ of Corti of 10 guinea pigs at five different intervals (5 min, 4 h, 24 h, 5 days and 28 days) after acoustic overstimulation. There was evidence of phagocytic cells only at 5 days after noise exposure. Dendritic macrophages were seen phagocytosing degenerating cells and debris in the tunnel of Corti and in the region of the outer hair cells. Transforming monocytes in this area and leukocytic accumulation within the spiral lamina vessel suggest that these cells may be derived from blood-borne monocytes. These cells may contribute to local disposal of intracochlear cell degeneration products and thus to healing of organ of hearing after induction of noise-induced damage.