丰富环境对孕期慢性应激所致子鼠学习能力影响的干预机制研究

Study on mechanism of enriched environment impaired learning and memory deficits induced by maternal chronic stress rat during pregnancy

目的从子鼠海马中核转录因子NF-κB的变化,来探讨丰富环境对孕期慢性应激子鼠学习能力的干预机制。方法建立孕期慢性应激大鼠模型,并采用丰富环境干预子鼠,利用水迷宫和Y-迷宫测定子鼠学习记忆能力、RTPCR和Western Blotting测定海马中NF-κB表达情况。结果模型组母鼠皮质酮增高,提示模型组大鼠处于应激状态。丰富环境后,子鼠血浆皮质酮降低(P<0.05);水迷宫中逃避潜伏期和跨平台次数、Y-迷宫中所需的训练次数和正确反应率情况均转好(P均<0.05);模型子鼠组海马NF-κB表达增高(P均<0.05)。结论丰富环境可以提高孕期受到应激因素影响的学习能力,与血浆皮质酮降低及海马NF-κB升高有关。

Objective To investigate the mechanism on enriched environment repair learning and memory deficits in offspring rats induced by maternal chronic stress during pregnancy from changes of hippocampal nuclear transcripyion factor-κB（NF-κB）. Methods A rat model of maternal chronic stress during pregnancy was mating from 3rd day during subjected to chronic unpredictable mild stress.Learning and memory responses were tested using Morris water maze and Ymaze.The expression of NF-κB mRNA and protein were respectively measured using RT-PCR and Western blotting in hippocampus. Results An elevation was observed in the plasma corticosterone level of rat model of maternal chronic stress during pregnancy and indicated model group rats in the stress state.Enriched environment treatment decreased offspring＇s plasma corticosterone level（P〈0.05）.The time of escape latency and the number of crossing platform of Morris water maze,the number of required training and the rate of correct response in Y-maze were improved（all P〈0.05）.Enriched environment boosted the average expression of hippocampal NF-κB mRNA and protein in the offspring of maternal stress during pregnancy（P〈0.05）. Conclusion The decrease in learning and memory of offspring can be repaired by enriched environment,the mechanism is related to reduced maternal plasma corticosterone and hippocampal NF-κB of offspring rats.