CAJ | 학술논문

目的探讨生理或病理状态下大鼠海马突触可塑性和空间学习记忆的相关性,为在体电生理实验和行为学实验结果的一致性提供依据.方法按照随机数字表随机选择SD大鼠38只,进行Morris 水迷宫空间学习记忆行为学和在体海马晚期长时程增强(L-LTP)电生理实验.主要指标包括大鼠连续5d定位航行试验寻找水下平台的逃避潜伏期、撤除平台后空间探索试验的目标象限游泳时间百分比以及高频刺激后3h的场兴奋性突触后电位(fEPSP).结果双侧海马注射4 nmol Aβ25-35明显伤害了大鼠水迷宫实验中的空间学习记忆能力(P＜0.05)和在体海马L-LTP(P＜0.05).正常对照组大鼠L-LTP与逃避潜伏期呈现明显负相关(r=-0.8306,P＜0.01),与目标象限游泳时间百分比呈现明显正相关(r=0.7709,P＜0.01)；AD模型组大鼠3h后fEPSP幅度也与逃避潜伏期具有明显负相关(r=-0.7675,P＜0.01),与目标象限游泳时间百分比正相关( r=0.8049,P＜0.01)；将两组大鼠数据合并后,海马L-LTP与逃避潜伏期和目标象限游泳时间百分比的相关性更高,分别为r=-0.9124 (P＜0.01)和r=0.9745 (P＜0.01).结论大鼠在体海马L-LTP电生理记录与空间学习记忆行为学测试结果具有良好的相关性,提示海马L-LTP可能是行为学改变的电生理机制,其损伤可以在一定程度上反映动物学习记忆功能障碍.
목적 탐토생리혹병리상태하대서해마돌촉가소성화공간학습기억적상관성,위재체전생리실험화행위학실험결과적일치성제공의거.방법 안조수궤수자표수궤선택SD대서38지,진행Morris 수미궁공간학습기억행위학화재체해마만기장시정증강(L-LTP)전생리실험.주요지표포괄대서련속5d정위항행시험심조수하평태적도피잠복기、철제평태후공간탐색시험적목표상한유영시간백분비이급고빈자격후3h적장흥강성돌촉후전위(fEPSP).결과 쌍측해마주사4 nmol Aβ25-35명현상해료대서수미궁실험중적공간학습기억능력(P＜0.05)화재체해마L-LTP(P＜0.05).정상대조조대서L-LTP여도피잠복기정현명현부상관(r=-0.8306,P＜0.01),여목표상한유영시간백분비정현명현정상관(r=0.7709,P＜0.01)；AD모형조대서3h후fEPSP폭도야여도피잠복기구유명현부상관(r=-0.7675,P＜0.01),여목표상한유영시간백분비정상관( r=0.8049,P＜0.01)；장량조대서수거합병후,해마L-LTP여도피잠복기화목표상한유영시간백분비적상관성경고,분별위r=-0.9124 (P＜0.01)화r=0.9745 (P＜0.01).결론 대서재체해마L-LTP전생리기록여공간학습기억행위학측시결과구유량호적상관성,제시해마L-LTP가능시행위학개변적전생리궤제,기손상가이재일정정도상반영동물학습기억공능장애.
Objective To investigate the correlation of hippocampal synaptic plasticity with spatial learning and memory under normal and pathological condition,and provide experimental evidence for the coincidence of hippocampal late-phase long-term potentiation (L-LTP) and behavioral experiments.Methods 38 SD rats were randomly divided into two groups,control and AD model.First,Morris water maze was used to test the ability of spatial learning and memory of rats.The escape latencies for rats to search for an underwater platform in 5 days of navigation tests and the swimming time percentage in target qtuadrant on the 6th day after withdrawing the platform in probe trails were recorded.Then,in vivo hippocampus L-LTP of field excitatory postsynaptic potential (fEPSP)in CA1 region was recorded after delivering high frequency stimulation (HFS).Results Bilateral intrahippocampal injection of 4 nmol amyloid β peptide ( Aβ 25-35 ) significantly impaired spatial learning and memory of rats in water maze tests,as well as in vivo hippocampal L-LTP.In control group,there was a significant negative correlation between the amplitude of fEPSP and the escape latency ( r =-0.8306,P ＜ 0.01 ) and a significant positive correlation between the amplitude of fEPSP and the swimming time percentage in target quadrant ( r=0.7709,P＜0.01 ).In AD model group,similar correlations were found,with a correlation coefficient of r =-0.7675 (P ＜0.01 ) and r =0.8049 (P ＜ 0.01 ),respectively.When putting all data from the two groups together,the hippocampal L-LTP was more correlated with escape latency ( r =-0.9124,P ＜ 0.01 ) and swimming time percentage ( r=0.9745,P＜0.01).Conclusion There is very close correlation between the hippocampal L-LTP and the spatial learning and memory behavior in rats,suggesting that the hippocampal L-LTP may be involved in the electrophysiological mechanism of spatial learning and memory in rats,and the impairment of L-LTP could partly represent the deficits in cognitive function of animals.