AMIKACIN INTOXICATION INDUCES APOPTOSIS AND CELL-PROLIFERATION IN RATORGAN OF CORTI

RECENTLY, an attempt at cochlear hair cell neodifferentiation has been reported in amikacin-treated rats. In the present study, we aimed to ascertain whether hair cell losses are mediated by apoptosis and wheth er cell proliferation occurs in damaged intoxicated cochleas. The resu lts show that apoptosis is responsible for hair cell losses and that c ell proliferation occurs in the region of the outer spiral sulcus but not in the region of Deiters cells and pre-existing hair cells. We sug gest that cell proliferation maintains a certain homeostasis in the nu mber of non-sensory cells and participates in epithelial scar formatio n. Neodifferentiated cells therefore probably arise from direct transd ifferentiation, which could be triggered by phagocytosis of apoptotic bodies. (C) 1998 Rapid Science Ltd.