LOWER DOSE OF AMINOGLYCOSIDE OTOTOXIC EXPOSURE CAUSES PRESYNAPTIC ALTERATIONS ASSOICATED WITH HEARING LOSS
LIU Ke
WANG Xiaoyu
LI Sijun
TANG Siquan
XU Yice
WANG Xuefeng
SUN Jianhe
YANG Weiyan
YANG Shiming
摘要：Objective To study presynaptic alternations of cochlear ribbons arising from aminoglycoside ototoxic stimuli in C57BL/6J mice. Methods Animals were injected with low dose gentamicin (100 mg/kg/day) for 14 days, From the 14th to 28th days, the mice were maintained free of gentamicin treatment. Immunohisto-chemistry labeling was employed to trace RIBEYE, a major presynaptic componment of ribbon synapses. RIBEYE/CtBP2 expression levels were assessed and compared with hearing threshold shifts. Auditory func-tion was assessed by auditory brainstem responses. The stereocilia of outer hair cells (OHCs) and IHCs was examined by scanning electron microscopy (SEM). Results Hearing thresholds were elevated with peak hearing loss observed on the 7th day after gentamicin exposure, followed by improvement after the 7th day. RIBEYE/CtBP2 expression directly correlated with observed hearing threshold shifts. Strikingly, we did not see any obvious changes in stereocilia in both OHCs and IHCs until the 28th day. Mild changes in stereocil-ia were only observed in OHCs on the 28th day. Conclusions These findings indicate that presynapse co-chlear ribbons, rather than stereocilia, may be sensitive to aminoglycoside ototoxic exposure in mice cochle-ae. A pattern of RIBEYE/CtBP2 expression changes seems to parallel hearing threshold shifts and suggests presynaptic response properties to lower dosage of aminoglycoside ototoxic stimuli.
机标关键词：scanning electron microscopyhearing losshair cells
资助基金：grants from the National Basic Research Program of China (973Program)(2012CB 967900)grants from the National Basic Research Program of China (2012CB967901)Beijing Natural Science Foundation (5122040)Additionally, this work was support-ed by grants from the China Postdoctoral Science Founda-tion(201003779)Additionally, this work was support-ed by grants from the China Postdoctoral Science Founda-tion(20100470103)the National Natural Science Foundation of China (NSFC)(31040038)
论文发表日期：2014-01-01
在线出版日期：2025-08-15（本平台首次上网日期，不代表文献的发表时间）
页数：7( 36-42 )
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