EFFECTS OF ENDOLYMPHATIC AND PERILYMPHATIC APPLICATION OF SALICYLATE IN THE PIGEON .2. FINE-STRUCTURE OF AUDITORY HAIR-CELLS

Large doses of salicylate are known to cause reversible ototoxic effec ts including fine structural alterations of the auditory hair cells in mammals. To investigate possible fine structural correlates of salicy late effects on pigeon auditory hair cells, the basilar papillae follo wing perilymphatic or endolymphatic application of salicylate were fix ed and processed for transmission electron microscopy. The pigeon audi tory hair cells possessed organelles typically described in avians. A single or multi-layered array of cisternae along the cytoplasmic side of the lateral plasma membrane, i.e. subsurface cisternae that are cha racteristic for mammalian outer hair cells, was not seen. The most pro minent fine structural alterations of hair cells after salicylate appl ication were an increase in the luminal width of smooth and rough endo plasmic reticulum as well as the frequent occurrence of prominent sing le-membrane-bound vesicles filled with electron-dense bodies. Based on the assumption that subsurface cisternae represent a specialized form of endoplasmic reticulum, the present findings indicate that the stru ctural correlates of salicylate toxicity are similar in mammalian and avian auditory hair cells.