噪声暴露后大鼠听皮层Parvalbumin表达水平的变化

发布时间：2018-01-09 12:19

本文关键词：噪声暴露后大鼠听皮层Parvalbumin表达水平的变化　出处：《安徽医科大学》2015年硕士论文　论文类型：学位论文

【摘要】：目的观察噪声暴露对大鼠听觉脑性诱发反应(Auditory brainstem response,ABR)的影响以及暴露后听皮层中钙结合蛋白中小清蛋白Parvalbumin(PV)表达水平的变化,研究噪声暴露对大鼠听皮层中PV表达量的影响,探讨噪声引起的听力损失、耳鸣及其他听觉异常等疾病的可能机制。方法将31只雄性SD大鼠随机分为实验组16只以及对照组15只。将实验组大鼠左耳暴露于带宽为一个倍频程,中心频率为16 k Hz,声音强度为116d B声强级的噪声中,暴露时间为1小时。分别于暴露前及暴露后第七天测定所有大鼠的双耳听性脑干诱发反应,评估其听力损失程度,应用免疫组化及蛋白质印记(Western Blot)方法检测噪声暴露后第七天大鼠听皮层中小清蛋白PV的变化,推测噪声暴露后大鼠听皮层中PV变化可能的原因及机制。结果(1)听力变化:暴露前实验组大鼠左右耳听阈均为20.00±5.0d B SPL,暴露后第七天左耳的听阈为75.0±5.0d B SPL,右耳听阈为18.3±2.9d B SPL,相较于暴露前,实验组大鼠左耳听阈明显提高。暴露后左右耳比较,左耳听阈明显较右耳高,差异具有统计学意义(P0.05);右耳听阈暴露前后无明显改变,差异无统计学意义(P0.05)。实验组右耳同对照组比较无明显改变,差异无统计学意义(P0.05)。(2)听皮层中PV表达水平的变化:噪声暴露后第七天,免疫组化及Western Blot检测结果均显示实验组大鼠左侧听皮层中PV的表达量较右侧高,同时实验组大鼠左侧大脑皮层中PV的表达量较对照组大鼠表达量高,差异均具有统计学意义(P0.05);实验组大鼠右侧听皮层中PV表达量同对照组比较,差异具有统计学意义(P0.05)。结论单耳噪声暴露后第7天,大鼠的暴露耳听阈明显提高,同时,在噪声暴露后,免疫组化及Western Blot结果均显示实验组大鼠听皮层PV升高,左侧表达量较右侧升高明显,这可能中枢神经系统抑制性降低,与对声音的过度刺激的一种保护作用、声音刺激后细胞代谢增强及兴奋性信号输入的增多有关,听皮层PV的变化可能与耳鸣及其它听觉功能改变有关。
[Abstract]:Objective to observe the auditory brain evoked response to noise exposure in rats. The effect of ABR and the changes of parvalbumin PVs expression level in auditory cortex after exposure. To study the effect of noise exposure on the expression of PV in the auditory cortex of rats and to explore the hearing loss caused by noise. Methods 31 male SD rats were randomly divided into experimental group (n = 16) and control group (n = 15). The center frequency is 16 kHz and the sound intensity is 116 dB. The exposure time was 1 hour. The auditory brainstem responses of all rats were measured before and 7th days after exposure to assess the degree of hearing loss. The changes of small and medium albumin PV in auditory cortex of rats 7th days after noise exposure were detected by immunohistochemistry and Western blot method. The possible causes and mechanism of PV changes in the auditory cortex of rats after noise exposure were speculated. Results 1) hearing changes: the hearing thresholds of the left and right ears of the experimental group were 20.00 卤5.0 dB SPL before exposure. The hearing threshold of left ear and right ear was 75.0 卤5.0d and 18.3 卤2.9d respectively, which was higher than that before exposure. The hearing threshold of the left ear in the experimental group was significantly higher than that in the right ear after exposure, and the difference was statistically significant (P 0.05). There was no significant change in the right ear hearing threshold before and after exposure, and the difference was not statistically significant (P 0.05). There was no significant change in the right ear in the experimental group compared with the control group. There was no significant difference in the expression of PV in the auditory cortex: 7th days after noise exposure. The results of immunohistochemistry and Western Blot showed that the expression of PV in the left auditory cortex of the experimental group was higher than that in the right. At the same time, the expression of PV in the left cerebral cortex of the experimental group was higher than that of the control group, and the difference was statistically significant (P 0.05). Compared with the control group, the expression of PV in the right auditory cortex of the experimental group was significantly higher than that in the control group (P 0.05). Conclusion on the 7th day after monaural noise exposure, the hearing threshold of exposed ears in the experimental group was significantly higher than that in the control group. After noise exposure, the results of immunohistochemistry and Western Blot showed that PV in auditory cortex of experimental group was increased, and the expression of left side was significantly higher than that of right, which may decrease the inhibition of central nervous system. The changes of PV in auditory cortex may be related to tinnitus and other auditory function changes.
【学位授予单位】：安徽医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R764

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