噪声暴露对大鼠ABR反应阈及听皮层谷氨酸脱羧酶67表达的影响

发布时间：2018-02-11 04:45

本文关键词： 大鼠噪声听性脑干反应听皮层谷氨酸脱羧酶　出处：《听力学及言语疾病杂志》2014年03期 　论文类型：期刊论文

【摘要】：目的研究噪声暴露对大鼠听性脑干反应(auditory brainstem response,ABR)及听皮层谷氨酸脱羧酶67(glutamic acid decarboxylase-67,GAD67)表达的影响。方法将21只健康雌性SD大鼠随机分为噪声暴露后0、7、14天组,每组7只,每组再随机分为对照组(3只)和暴露组(4只);将暴露组大鼠暴露于频率4kHz以上、100dB SPL白噪声2小时建立噪声性听觉损伤的动物模型,对照组大鼠不作任何处理;分别于噪声暴露前及暴露后0天(0.5~2小时)、第7天、第14天时检测各组大鼠的ABR反应阈;取噪声暴露后0天(2~4小时)、第7天、第14天各组大鼠的听皮层切片,用免疫组织化学的方法标记各组听皮层中GAD67阳性神经元数量。结果①在噪声暴露后0.5~2小时暴露组大鼠的ABR反应阈明显高于对照组(P0.05),14天时基本恢复正常;②在噪声暴露后2~4小时暴露组大鼠听皮层GAD67阳性神经元数量(78.76±16.11个/mm2)明显多于对照组(38.43±9.27个/mm2)(P0.05),第7天和第14天时暴露组GAD67阳性神经元数量(32.22±8.61个/mm2和29.55±11.61个/mm2)明显低于对照组(43.58±12.87个/mm2和43.14±12.44个/mm2)(均P0.05)。结论噪声暴露使大鼠ABR反应阈发生了暂时性阈移,听皮层GAD67阳性神经元数量在噪声暴露后先增多后减少,可能与噪声性聋发病机制有关。
[Abstract]:Objective to study the effects of noise exposure on the expression of auditory brainstem responseABR and glutamate decarboxylase-67 in auditory cortex of rats. Methods Twenty-one healthy female SD rats were randomly divided into two groups, 7 rats in each group. Each group was randomly divided into control group (n = 3) and exposure group (n = 4). The rats in the exposure group were exposed to 100 dB SPL white noise at frequencies above 4kHz for 2 hours to establish the animal model of noise-induced hearing impairment, and the rats in the control group were not treated with any treatment. Before and 0 days after noise exposure, the ABR response thresholds were measured on the 7th day and the 14th day, respectively, and the auditory cortex sections of the rats in each group were taken 0 days after noise exposure for 2 hours, 7 days and 14 days, respectively. The number of GAD67 positive neurons in the auditory cortex of each group was labeled with immunohistochemical method. Results 1 the ABR response threshold of the rats in the exposure group was significantly higher than that in the control group at 0. 5 and 2 hours after noise exposure on the 14th day after noise exposure. 2 hours after exposure, the number of GAD67 positive neurons in the auditory cortex of rats in the exposure group (78.76 卤16.11 / mm2) was significantly higher than that in the control group (38.43 卤9.27 / m-2 / mm2), and the number of GAD67 positive neurons in the exposed group was 32.22 卤8.61 / mm2 and 29.55 卤11.61 / mm2 on the 7th and 14th days after exposure respectively, which was significantly lower than that in the control group (43.58 卤12.87 / mm2 / mm2). And 43.14 卤12.44 / mm2 (all P 0.05N). Conclusion noise exposure causes transient threshold shift of ABR reaction threshold in rats. The number of GAD67 positive neurons in auditory cortex increased first after noise exposure and then decreased, which may be related to the pathogenesis of noise-induced deafness.
【作者单位】：安徽医科大学附属安徽省立医院耳鼻咽喉头颈外科;
【基金】：国家自然科学基金(81200741) 安徽省自然基金(11040606M174)资助
【分类号】：R764

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