快速老化小鼠学习记忆能力与海马CA1区神经元丢失相关性探讨

摘要

Objective:To explore the relationship between the decline of learning-memory ability and neuronal loss of hippocampal CA1 region in senescence accelerated mouse P8.Methods:Fourteen 7-month-old healthy male SAMP8 were used as experimental group,and fourteen 7-month-old healthy male SAMR1 were choosed as normal control group.We Detected the spatial learning and memory of mice in each group by Morris water maze (MWM)test,and observsed the number and morphology of neuron in hippocampal CA1 region by Nissl staining.Results:The MWM test showed that the escape latency of SAMP8 group was obviously longer than that in SAMR1 group(P <0.01),and the times of crossing platform also decreased significantly (P < 0.01 ).The Nissl staining demonstrated that the numbers of neuron in hippocampal CA1 region of SAMP8 group drastically reduced(P <0.01)compared with controls.A negative correlation were observed between the escape latency of the fifth day in positioning navigation training and the numbers of neuron in hip-pocampal CA1 region(P<0.01),but the times of crossing platform were positive correlated with the numbers of neuron were (P < 0.05 ).Conclusion:The decrease ability of learning-memory was closely related to the neuronal loss of hippocampal CA1 region in SAMP8 group,thus provided strong evidence for the senescence accelerated mouse P8 as an ideal animal model of researching AD,and also offered new direction for the research and treatment of AD in the future.%目的：探讨快速老化小鼠学习记忆能力下降与海马 CA1区神经元丢失的相关性。方法：选用健康雄性7月龄SAMP8和SAMR1小鼠各14只,通过Morris水迷宫实验检测各组小鼠空间学习记忆能力,Nissl染色观察海马CA1区神经元的数量和形态的变化。结果：与SAMR1对照组相比,SAMP8小鼠逃避潜伏期明显延长(P<0.01),跨越平台次数明显减少(P<0.01)；海马CA1区神经元数量明显减少(P<0.01)；Morris 水迷宫实验定位航行训练第五天逃避潜伏期与海马 CA1区神经元数量均呈负相关(P<0.01),跨越平台次数与海马CA1区神经元数量均呈正相关(P <0.05)。结论：SAMP8小鼠海马CA1区神经元的减少与学习记忆能力密切相关,为其作为研究AD较理想的动物模型提供了有力的证据,也为今后该疾病的研究及治疗提供了方向。