Enhanced auditory brainstem response by forward acoustic masking as an index of subjective tinnitus

【作者】 刘晓鹏； 陈林；

【机构】 中国科学技术大学听觉研究实验室；

【摘要】 In the present study,we demonstrated that forward acoustic masking can boost,rather than suppress,the auditory brainstem response(ABR)in rats treated with a high dose of sodium salicylate(Na Sal),a tinnitus inducer.We first carried out this experiment under two conditions:(1)the forward masker and the probe were presented to both ears(diotic paradigm);(2)the forward masker was presented to one ear and the probe to the other ear(dichotic paradigm).We found that only when the stimuli were presented using the diotic,rather than the dichotic,paradigm could forward acoustic masking enhance the ABR in the rat treated with Na Sal(300 mg/kg).The enhancement occurred at the high frequencies(16,24,32 k Hz)at which the animals demonstrated a tinnitus-like behavior as revealed using the gap prepulse inhibition of acoustic startle paradigm.We then administered vigabatrin,a GABA transaminase inhibitor,in the animals to suppress Na Sal-induced tinnitus.The vigabatrin treatment successfully prevented the ABR enhancement from forward acoustic masking.These findings demonstrate that the observed enhancement of the ABR by forward acoustic masking originates in the auditory pathway unilateral to the stimulated ear and is closely associated with Na Sal-induced tinnitus.The enhanced ABR by forward acoustic masking suggests a promising objective measure of subjective tinnitus.更多还原

【Abstract】 In the present study,we demonstrated that forward acoustic masking can boost,rather than suppress,the auditory brainstem response(ABR) in rats treated with a high dose of sodium salicylate(Na Sal),a tinnitus inducer.We first carried out this experiment under two conditions:(1) the forward masker and the probe were presented to both ears(diotic paradigm);(2) the forward masker was presented to one ear and the probe to the other ear(dichotic paradigm).We found that only when the stimuli were presented using the diotic,rather than the dichotic,paradigm could forward acoustic masking enhance the ABR in the rat treated with Na Sal(300 mg/kg).The enhancement occurred at the high frequencies(16,24,32 k Hz) at which the animals demonstrated a tinnitus-like behavior as revealed using the gap prepulse inhibition of acoustic startle paradigm.We then administered vigabatrin,a GABA transaminase inhibitor,in the animals to suppress Na Sal-induced tinnitus.The vigabatrin treatment successfully prevented the ABR enhancement from forward acoustic masking.These findings demonstrate that the observed enhancement of the ABR by forward acoustic masking originates in the auditory pathway unilateral to the stimulated ear and is closely associated with Na Sal-induced tinnitus.The enhanced ABR by forward acoustic masking suggests a promising objective measure of subjective tinnitus.更多还原