帕金森病模型大鼠行为学评价与黑质神经元凋亡的相关研究

Behavior and Neuronal Apoptosis in Substantia Nigra of Rats with Parkinson's Disease

目的检测帕金森病(PD)模型大鼠行为学及黑质神经元凋亡的相关指标。方法将6-羟基多巴胺(6-OHDA)通过立体定位仪注入大鼠右侧纹状体制备PD模型,5周后检测行为学指标;酪氨酸羟化酶(TH)组化染色观察各组大鼠右侧黑质神经元形态,Hoechst33258染色了解其凋亡情况,Western blotting方法检测黑质内caspase-3蛋白表达。结果成功筛选的15只PD模型大鼠在露台Morris水迷宫实验中,与正常对照组及假手术组同侧相比,其寻台速度下降,时间延长(P<0.05);在平衡杆实验中,其潜伏期和过杆时间增加(P<0.05);模型组右侧黑质TH阳性神经元明显减少,该区域凋亡细胞明显增多,且caspase-3蛋白表达显著增高。结论6-OHDA诱导黑质内多巴胺(DA)神经元凋亡与其胞内caspase-3表达增高相关,模型大鼠在露台Morris水迷宫和平衡杆实验中行为学改变与TH免疫组化染色及Hoechst33258染色结果吻合。

Objective To assess rat behavior,observe apoptotic morphology of neurons and measure expression of caspase-3 in substantia nigra（SN） of Parkinson＇s disease（PD） animal model. Methods 6-OHDA was stereotacticly injected into the right striatum of the rats at two sites to produce PD models. After 5 weeks,the behavior tests including modified Morris Water Maze and narrow beam test were measured. Then tyrosine hydroxylase （TH） histochemistry,Hoechst 33258 staining,Western blotting for caspase-3 in right substantia nigra was separately conducted.Results Escape velocity significantly decreased and its latency was obviously enlarged in modified Morris Water Maze,and the latency and total time in narrow beam test were also markedly increased （P〈0.05） in 15 successful PD rats compared with either the sham group or the normal group. Furthermore,there were obvious less TH-positive neurons in lesioned SN while more apoptotic cells appeared there. In addition,the expression of caspase-3 was highly upregulated in lesioned SN.Conclusion 6-OHDA induced neuronal apoptosis in SN is associated with high levels of caspase-3,and the results of rat behavior tests are correspondent with the morphological changes including TH immunohistochemistry and Hoechst 33258 staining. Thus modified Morris Water Maze and narrow beam test are beneficial for assessments of effects of new drugs in PD animal model.