THE ALTERATION OF ULTRASTRUCTURE AND IMMUNOREACTIVITY OF HUMAN EMBRYONIC ORGAN OF CORTI TISSUE-CULTURE AFTER EXPOSURE TO AMINOGLYCOSIDE (NEOMYCIN) OTOTOXICITY

Using electron microscopy and GABA immunohistochemistry we evaluated t he effects on human embyronic organ of Corti tissue culture of exposur e to the ototoxic aminoglycoside antibiotic neomycin at a dose of 1 mM for 48 to 96 hrs. Neomycin induces the formation of multilamellar mye loid structures. These lesions, found only in the basal coil but both in inner and outer hair cells, were characteristic of the membrane-ass ociated neomycin-induced damage. A large amount of lipofucsin and nume rous lipoid vacuoles as well as vesicle-filled mound-like protrusions were also observed after exposure to neomycin. It seems there is no ob vious effect on GABAergic innervation.