Aβ25-35伤害大鼠空间学习记忆和在体海马长时程增强的联合研究  

The combined study on Aβ25-35 induced impairment in spatial learning and memory and hippocampal long-term potentiation in rats

作　　者：周丽薇[1] 武美娜[1] 韩维娜[1] 高秀萍[1] 祁金顺[1] 

机构地区：[1]山西医科大学生理学系,细胞生理学省部共建教育部重点实验室,太原030001

出　　处：《神经解剖学杂志》2012年第3期263-267,共5页Chinese Journal of Neuroanatomy

基　　金：教育部高等学校博士点基金(20101417110001);山西省自然科学基金(2010011049-32009011054-2);山西省自然科学基金(2011021036-2);细胞生理学省部共建教育部重点实验室主任基金(2010-08)

摘　　要：目的:探讨海马内注射β-amyloid protein 25-35(Aβ25-35)所致Alzheizer’s病(AD)模型大鼠空间学习记忆功能障碍的海马突触可塑性长时程增强(LTP)机制,为联合开展AD动物行为学和在体电生理学研究提供实验证据。方法:在脑立体定位仪上给予大鼠双侧海马分别注射4 nmol/L Aβ25-35或等体积生理盐水每侧2μl,手术后恢复2周,每只大鼠依次进行行为学和电生理两部分实验。首先,利用Morris水迷宫进行空间学习、记忆功能测试;之后,进行在体海马CA1区场兴奋性突触后电位(fEPSP)引导记录实验,观察突触可塑性指标长时程增强(LTP)的改变。结果:与对照组相比,海马内注射Aβ25-35大鼠的空间学习记忆功能和在体海马突触可塑性LTP均有改变,其中:逃避潜伏期和逃避距离明显增加(P<0.01);目标象限内游泳时间和距离明显缩短(P<0.01);在体海马LTP幅度显著降低(P<0.01)。结论:海马内注射Aβ25-35可导致大鼠空间学习记忆功能障碍;联合实验中Aβ25-35同样可引起在体海马LTP改变。提示同批动物先后进行行为学和电生理学测试的方法是可行的,行为学实验不会影响后续LTP的实验结果。因此,本实验为行为学改变后进行在体LTP机制探讨提供了实验依据,为有效开展行为学和电生理学实验提供了思路。Objective：To explore the long-term potentiation mechanism for hippocampal injection of β-amyloid protein 25-35（Aβ25-35） induced impairment of spatial learning and memory in rats,and to provide experimental evidence for combining animal behavior test with in vivo electrophysiological experiment in Alzheizer ＇ s disease（AD） related animal.Methods： Aβ25-35（4 nmol/L） or normal saline,2 μl each lateral was injected into both sides of hippocampuses of rats.Two weeks later,behavioral test and electrophysiological experiment were performed.First,the spatial learning and memory was examined by using Morris Water Maze test.Then the same rats were used to record the field excitatory postsynaptic potentials（fEPSPs） and long term potentiation（LTP） of fEPSPs in the CA1 region of hippocampus.Results： Compared with control group,the spatial learning and memory and synaptic plasticity of rats in the group of Aβ25-35 treatment were changed,with an increased escape latency and escape distance（P0.01）,a decreased time and distance percentage in target quadrant（P0.01） and a synchronous in vivo hippocampal LTP suppression（P0.01）.Conclusion： Hippocampal injection of Aβ25-35 resulted in spatial memory impairment,together with hippocampal LTP suppression in the same rats,suggesting that behavior test will not affect the following in vivo LTP recording,and it is practicable to perform behavioral and electrophysiological experiments in the same batch of animals.Therefore,the present study provided an evidence and a new idea for designing behavioral experiments together with electrophysiological recording.

关 键 词：AΒ25-35 空间学习记忆 长时程增强 MORRIS水迷宫 阿尔茨海默病 海马内注射 大鼠 

分 类 号：R741[医药卫生—神经病学与精神病学]