Organ culture of the late embryonic inner ear as a model for ototoxicity studies

The 16th gestational day inner ear of the CBA/CBA mouse was used in an organ culture system as a model for ototoxicity studies. The specimens in culture were exposed to 1, 10, 100 and 1 000 micrograms/ml of gentamicin base during 1-5 days in culture. Minor changes were found after only one day of exposure. Pathological changes of vestibular hair cells characteristic for aminoglycoside antibiotics occurred after exposure to 1 and 10 micrograms/ml. Concentrations of 100 and 1 000 micrograms/ml caused a general toxicity with destruction of the whole morphology of the crista ampullaris. Hair cells were, however, more affected than were supporting cells. Initially, variation of hair cell damage occurred within each crista and between different cristae but this became less apparent after 5 days in culture. The 16th gestational day organ culture system can serve as a useful model system with many controlled experimental parameters in the testing of ototoxic drugs.