Growth factor treatment enhances vestibular hair cell renewal and results in improved vestibular function

The vestibules of adult guinea pigs were lesioned with gentamicin and then treated with perilymphatic infusion of either of two growth factor mixtures (i.e., GF I or CF II). GF I contained transforming growth factor alpha (TG F alpha), insulin-like growth factor type one (IGF-I), and retinoic: acid ( RA), whereas CF II contained those three factors and brain-derived neurotro phic: factor. Treatment with GF I significantly enhanced vestibular hair ce ll renewal in ototoxin-damaged utricles and the maturation of stereociliary bundle morphology. The addition of brain-derived neurotrophic factor to th e GF II infusion mixture resulted in the return of type 1 vestibular hair c ells in ototoxin-damaged cristae, and improved vestibular function. These r esults suggest that growth factor therapy may be an effective treatment for balance disorders that are the result of hair cell dysfunction and/or loss .