Effects of Intratympanic Injection of the Ototoxic Drug on the Frog Semicircular Canal

Abstract

Effects of the intratympanic and intralabyrinthine injections of Gentamicin on the posterior semicircular canal were studied using bull frog. After intratympanic injection of Gentamicin (20 mg), only mild changes of the sensory cells were observed. They were slight loss of the sensory cells and bulging of the cell surface. The posterior ampullary nerve action potentials reduced to approximately 68% of the noninjection ear. When Gentamicin (4 mg) was injected into the labyrinth, more pronounced damage was observed. The action potentials likewise reduced markedly.