噪声对幼鼠学习记忆行为及海马区Glu阳性神经元表达的影响

THE INFLUENCE OF NOISE ON LEARNING MEMORY BEHAVIORS IN JUVENILE RATS AND EXPRESSION OF GLU POSITIVE NEURONS IN HIPPOCAMPUS

[目的]拟观察噪声对幼鼠学习记忆及海马区Glu阳性神经元表达的影响,探讨噪声对幼鼠学习记忆能力的影响及其机制。[方法]将24只Wistar幼鼠,随机分为噪声组和对照组,噪声组在90dB(A)噪声下持续暴露1个月,用Morris水迷宫测定幼鼠的空间学习记忆能力,用免疫组化法观察海马区Glu阳性神经元的表达。[结果]在Morris水迷宫试验中,噪声组寻找平台的潜伏期较对照组延长(P﹤0.05),末次跨台次数较对照组明显减少(P﹤0.01)。噪声组海马区Glu阳性神经元的数量及染色强度较对照组显著降低。[结论]噪声可使幼鼠学习记忆能力下降,这可能与海马区Glu的合成减少,抑制了习得性长时程突触增强有关。

[Objective] To observe and probe the effect that noise exposure has upon the expression of Glu positive neurons in hippocampus, in order to study the influence and mechanism that noise poses on the capability of learning and memory in juvenile rats. [Methods] Tetracosa-Wistar juvenile rats were randomly divided into noise group and control group, The nbise group was exposed to 90 dB （A） noise for one month; The capability of learning and memory of juvenile rats was measured by means of Morris water maze test. An immunohistochemical method was used to investigate the expression of glutamic acid positive neurons in hippocampus. [ Results ] In training of Morris water maze, the mean escape latency of juvenile rats in the noise group were longer than that in the control group and the frequency to bestride platform of juvenile rats in the noise group were less than that in the control group. The number of glutamic acid positive neurons and the magnitude of tinction in hippocampus of juvenile rats in the noise group were significantly decreased compared With that in the Control group. [Conclusion] Noise impairs the capacity of learning and memory ; this impairment may be related with the reduction of glutamic acid contents and the inhibition of learning dependent long term potentiation in hippocampus.