乙醇对小鼠认知能力的影响及其与海马M1受体的关系

Correlation Study of Cognitive Disorder Induced by Ethanol and M1 Receptor in Hippocampus in Mice

目的研究乙醇对小鼠认知能力的影响及其与小鼠海马结构M1毒蕈碱型乙酰胆碱受体(M1受体)含量变化的关系,进一步揭示乙醇引起脑损伤的机制。方法将60只雌性小鼠随机分为对照组、8%、16%、32%乙醇给药组,以0.2 m L/10 g给药8周后,Morris水迷宫检测小鼠学习记忆能力,ELISA法检测各组小鼠海马结构中M1受体含量的差异。结果与各自第1天比较,各实验组小鼠第5天逃避潜伏期均值均明显缩短。各乙醇组小鼠第5天逃避潜伏期均值与对照组第5天均值比较,无统计学差异。16%、32%乙醇组小鼠在靶象限活动时间明显短于对照组。各乙醇组小鼠海马结构内M1受体含量与对照组比较明显下降,且与乙醇摄入量呈剂量依赖关系。结论海马结构M1受体含量降低是乙醇引起小鼠记忆能力下降的原因之一。

t Objective To investigate the effect of ethanol on level of the main hippocampal subtype of muscarinic receptor （ M1 ） in mice, and evalu- ate whether the content change on this receptor could be linked with alterations in cognition, so as to further reveal the mechanism of brain damage in- duced by ethanol Methods Sixty female mice were randomly divided into four groups. The model mice were induced by intragastric administration of ethanol at dose of 8%, 16%, and 32% respectively ofO.2 mL/10 g for 8 weeks according to the protocol, and control group were treated with intra- gastric administration of distilled water. The capability of learning and memory were examined by Morris water maze, and ELISA method was used to measure the M1 receptor content in hippocampus in each group of mice. Results Compared with first day, the mean escape latency period on the fifth day was significantly shortened in each group. There was no significant difference between ethanol and control group for the mean escape latency period on the fifth day. Compared with the control group, the active time in the target quadrant was significantly shortened in 16% and 32% ethanol group. M1 receptor content in hippocampus formation was significantly decreased in all the ethanol group mice. The ethanol concentration was nega- tive correlated with the M1 receptor content. Conclusion Chronic alcoholism can induce the memory impairment in mice, which might be associat- ed with the low level of M1 receptor subtype in hippocampus of mice.