C-fos Expression in Brain Stem of Rats after Salicylic Acid Treatment / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Subjective tinnitus, a distracting internal noise, is experienced by humans. Tinnitus is evoked by salicylic acid treatment in rats as confirmed by Jastreboff in 1994 in an animal behavior model of tinnitus with salicylic acid. The objective of this study is to evaluate c-fos expression in the brain stem of rats after salicylic acid treatment. MATERIALS AND METHOD: After salicylic acid (450 mg/kg) and saline treatment (450 mg/kg), c-fos immunohistochemical staining expression in the auditory and nonauditory brain stem nuclei were observed. RESULTS: Many immunoreactive cells were observed in the Locus Ceruleus of the salicylic acid treated animals, but not in the saline treated animals. No immunoreactive cells were found in the auditory brain stem nuclei. CONCLUSION: The Locus Ceruleus is the nucleus of the brain stem and produce norepinephrine which results in arousal of the neuronal activity for stress. These results suggest that salicylic acid may evoke tinnitus through a combined effect on the auditory and nonauditory brain nuclei. It seems possible that the interaction of these effects at particular locations of the brain causes tinnitus.