噪声对小鼠学习和记忆的影响及其相关机制的研究

发布时间：2018-06-19 03:09

本文选题：噪声 + Morris水迷宫　；参考：《华中师范大学》2008年硕士论文

【摘要】： 噪声对健康的损害可累及多个系统,但对神经系统的影响最为严重。本实验研究了噪声干扰对昆明小鼠(Mus musculus Km)空间性学习和记忆以及情绪性学习和记忆的影响,并对其机制进行了初步探讨。研究选用3周龄昆明小鼠80只,分为正常对照组和噪声干扰组,其中噪声干扰组每天不定期暴露于90 dB SPL的白噪声2小时。噪声干扰6周后通过Morris水迷宫和电跳台法检测动物的学习和记忆能力。同时我们检测了噪声暴露后1周、3周和6周动物颞皮层、海马和下丘3个部位的超氧化物歧化酶活性和丙二醛表达水平的变化,并采用5-溴脱氧尿嘧啶核苷标记法观察两组动物大脑新生神经元数目的变化,用TUNEL法检测大脑神经元的凋亡情况,以期对其机制进行探讨。研究结果发现:(1)噪声暴露早期动物表现出焦虑、惊恐等症状,同时活动量增大,后期动物体重增长缓慢,反应迟钝,活动量减少。(2)行为学检测结果发现,在Morris水迷宫训练的第2天和第3天,噪声组小鼠找到平台的潜伏期明显大于对照组(P＜0.05);电跳台结果表明,第1天,两组动物的跳上潜伏期延长,错误次数没有明显差异,第2天,噪声组与对照组相比,跳上潜伏期延长,错误次数增加(P＜0.01),说明其情绪记忆受到了影响;(3)噪声暴露1周、3周和6周后,动物颞皮层、海马和下丘部位的超氧化物歧化酶活性明显高于对照组(P＜0.05);丙二醛含量增加(P＜0.05),且随噪声时间延长下降;(4)噪声暴露组海马CA3区新生神经元数目较正常组减少,凋亡神经元数目增多。以上结果表明:90 dB白噪声暴露(2h/天)可导致昆明小鼠空间性学习记忆能力和情绪性记忆能力受损。噪声干扰的前期可导致体内过氧化反应增强,体内氧化应激代谢产物增加,同时体内的抗氧化应激的能力也增强,使机体清除氧自由基的能力增强。噪声干扰的晚期机体清除氧自由基的能力减弱,凋亡神经元数目增加,同时小鼠海马新生神经元减少。
[Abstract]:Noise damage to health may involve multiple systems, but the most serious impact on the nervous system. The effects of noise interference on spatial learning and memory and emotional learning and memory in Kunming mice were studied and the mechanism was discussed. Eighty Kunming mice aged 3 weeks were divided into normal control group and noise interference group. The noise interference group was exposed to 90 dB SPL white noise for 2 hours every day. After 6 weeks of noise disturbance, the learning and memory abilities of animals were measured by Morris water maze and electric jump table method. At the same time, we measured the activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) expression in temporal cortex, hippocampus and inferior colliculus of animals at 3 and 6 weeks after noise exposure. 5-bromodeoxyuridine labeling method was used to observe the number of neonate neurons in the brain of the two groups and Tunel method was used to detect the apoptosis of brain neurons in order to explore its mechanism. The results showed that the animals showed anxiety, panic and other symptoms in the early stage of noise exposure, but at the same time they increased their activities, but later they grew slowly, were slow to react, and their activities decreased. 2) Behavioral tests found that, On the 2nd and 3rd day of Morris water maze training, the latency of finding platform in the noise group was significantly higher than that in the control group (P < 0.05). On the second day, compared with the control group, the latency of jumping was prolonged and the number of errors increased (P < 0.01), which indicated that the emotional memory was affected by noise exposure for 1 week, 3 weeks and 6 weeks, the temporal cortex of the animals was exposed to noise. The activity of superoxide dismutase (SOD) in hippocampus and inferior colliculus was significantly higher than that in control group (P < 0.05), and the content of malondialdehyde increased (P < 0.05), and decreased with the increase of noise time. The number of apoptotic neurons increased. The above results indicated that the spatial learning and memory ability and emotional memory ability of Kunming mice were impaired when exposed to 90 dB white noise for 2 h / day. The early stage of noise interference can lead to the increase of peroxidation in vivo, the increase of metabolites of oxidative stress in vivo, and the enhancement of the ability of anti-oxidative stress in vivo, so that the ability of scavenging oxygen free radicals can be enhanced. The ability of scavenging oxygen free radicals was decreased, the number of apoptotic neurons increased and the number of hippocampal neonate neurons decreased in the late stage of noise interference.
【学位授予单位】：华中师范大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R363

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