长时间声音暴露对小鼠学习记忆行为及海马组织的影响

Effects of Long Term Sound Exposure on the Learning and Memory Behaviors and Hippocampus of Mice

目的:观察长时间声音暴露对小鼠学习记忆行为及海马组织的影响。方法:将30只小鼠随机分为噪声组、乐音组、对照组,噪声组、乐音组分别每天在100 dB噪声和40 dB乐音下暴露24 h并持续10 d,对照组不做任何处理;用Y型迷宫测试小鼠的学习记忆行为,HE染色观察小鼠海马神经元细胞数目及形态,免疫组织化学方法检测神经元中乙酰胆碱酯酶(AChE)含量的变化。结果:经噪声及乐音暴露后,小鼠反应和学习行为迟钝,海马神经细胞数目减少并出现异型,AChE含量增加,噪声组与正常组比较差异有统计学意义(P<0.05)。结论:长时间的声音暴露,无论是噪声还是乐音,对小鼠学习记忆行为均有抑制作用,高强度的噪声还能使海马神经元数目结构出现明显异常,AChE含量升高,导致ACh水平进一步降低,加重学习记忆功能的缺损。

Objective： To investigate the influences of long term sound exposure on the learning and memory behaviors and hippocampus of mice. Methods ： Thirty mice were randomly divided into noise group, music group, and control group. The mice in noise group and music group had been in 100 decibels noise and 40 decibels music for 10 days, respectively. Controls were raised according to normal method. The learning and memory behaviors of mice were assayed by ~ - maze test. The number and morphous of hippocampal neurons were assayed by I-IE staining, and the content of acetylcholinesterase （AChe） in the hippocam- pal neurons was assayed by immunohistochemical method. Results： After long term exposure to noise or music, the reaction and learning behaviors of mice were slow. The number of hippocampal neurons decreased, and atypical neurons appeared. The con- tent of AChe increased. The differences between noise group and control group were significant. Conclusion： Long term sound ex- posure has inhibition on the learning and memory behaviors of mice. High intensity noise may result in abnormal number and structure of hippocampal neurons, and increase the content of AChe in hippocampal neurons.