[The mechanism of protection by sound conditioning from acoustic trauma].

Aim: To investigate the mechanism of protection by sound conditioning from acoustic trauma.

Methods: Sound conditioning experimental model of animals was established. The expression of CaM, HSP70 and F-actin in hair cells were examined with the method of immunohistochemistry. Free calcium concentration in hair cells was observed by LSCM at the same time. Quantitative investigation was devised to assess the changes of F-actin, CaM, HSP70 and intracellular calcium concentration in hair cells.

Results: The expression of CaM, HSP70 and F-actin all showed an increased trend after noise exposure. HSP70 and F-actin expressed significantly more in group CH than that expressed in group H. Compared with group H, the expression of CaM showed an increased trend in group CH. Elevation of intracellular calcium concentration could be resulted from noise exposure. The calcium concentration in group H was significantly higher than that in group C and group CH.

Conclusion: A suitable sound conditioning can make the auditory system of guinea pig more resistant to noise trauma. The strengthened cytoskeleton system and the intracellular calcium homeostasis play a critical role in the protective mechanism of sound conditioning.