Effect of noise on aFGF activity in rat cochlea nuclei

Objective:aFGF-like immunoreactivity （aFGF-LI） was studied with qantitative immunocytochemistry in the rat cochlear nuclei after noise exposure of different intensity.Methods:Using the method of noise expose and quantitative imunocyte chemistry.Results:In group high noise exposure （130 db SPL, 8 kHz white noise）, aFGF-LI was seen to have decreased one day after exposure and did not recover untill one to two months. On the other hand, in grouup low noise exposure （120 dB SPL）, aFGF-LI was also seen to be reduced one day after noise exposure, but, it recovered during one to two months. The changes in optical density of aFGF-LI in the neurons of the cochlear nuclei were seen to be associated with corresponding changes in brain stem responses. Conclusion:This study shows that noise exposure cause a downregulation of aFGF both in the cochlear nuclei neurons and spiral ganglion.