MPTP对小鼠空间学习和记忆能力的影响

目的 观察1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)对小鼠学习和记忆行为的影响。方法C57BL/6小鼠皮下注射8d MPTP(20mg/kg)。测定小鼠爬竿和游泳时间。Morris水迷宫实验测定小鼠寻找站台的搜索策略、逃逸潜伏期、游泳距离、游泳时间、20％和40%边缘区域、中心区域所占百分比。免疫细胞化学观察黑质酪氨酸羟化酶(TH)阳性多巴胺能神经元变化。结果 MPTP小鼠的爬竿和游泳分数明显低于正常对照组(P<0.01)。MPTP小鼠黑质致密部TH免疫反应阳性神经元数目明显少于正常对照组(P<0.01),TH免疫反应阳性神经元灰度明显低于对照组(P<0.01),黑质致密部多巴胺能神经元脱失,残存神经元免疫反应活性代偿性增强。Morris水迷宫测试表明MPTP小鼠搜寻策略较对照组变差,寻找站台潜伏期较对照组明显延长(P<0.01),在目标象限游泳路径长度和时间所占百分比较对照组明显降低(P<0.05),搜寻轨迹中20%和40％边缘区域所占百分比较对照组明显增高(P<0.05),中心区域所占百分比较对照组明显降低(P<0.01)。结论 MPTP小鼠在黑质多巴胺能神经元损伤后,运动协调性下降并伴有空间学习记忆能力的下降

Effects of 1-methyl-4-phenyl-1 ,2,3,6-tetrahydropyridine on the ability of spatial learning and memory in mice

Objective To observe the ability of spatial learning and memory in mice treated with 1-meth-yl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP). Methods C57BL/6 mice were injected with MPTP ( 20mg/ kg, s. c. ) for 8 days, then the pole test and swimming test were performed. Morris water maze was to test the search strategy , escape latency,the percentage of swimming distance and time, 20% and 40% area, center area. Immunocytochemistry was used to observe the change of TH-IR positive neurons in substantia nigra. Results The score of pole and swimming test decreased compared with the control ones( P<0. 01). MPTP mice showed disability of pole and swimming. The number of TH-IR neurons reduced ( P<0. 01) and the mean grey of TH-IR neurons decreased ( P<0.01) compared with the control ones . Loss of TH-IR neurons occurred in substantia nigra pars compacta. Morris water maze was to show that compared with the control ones, search strategy became worse the search latency of MPTP mice prolonged ( P<0.01 ) , the time and the distance spent in the trained quadrant decreased( P <0.05). Among total length, 20% and 40% area increased with the decrease of center area ( P<0.05) compared with the control group. Conclusion After the damage of dopaminergic neurons in substantia nigra, MPTP mice made by above method lost the motor harmony and had the deficit of the spatial learning and memory.