Hair cell regeneration after streptomycin toxicity in the avian vestibular epithelium.

Recent reports documented the ability of the posthatch avian vestibular epithelia to produce hair cells continually at a low rate. This project was designed to investigate whether, in addition, the chicken vestibular system is capable of regenerating its sensory epithelium in response to a lesion. Aminoglycoside injections were given to young birds in order to damage the vestibular epithelium. Tritiated thymidine injections were used to label cells produced in response to the lesion. Treatment and age-matched control animals were killed at 1 day, 20 days, or 60 days after aminoglycoside injections, and vestibular organs were processed for autoradiography. Our results show that the chicken vestibular sensory epithelium is capable of regenerating hair cells after severe damage. Moreover, the epithelium is capable of complete anatomical recovery. Finally, drug damage increases the pace at which hair cells are replaced, compared to the rate of hair cell turnover in untreated tissue.