血管性痴呆大鼠认知功能及nNOS的表达

Cognitive function and expression of nNOS in vascular dementia rats

目的探讨血管性痴呆(VD)大鼠认知功能、海马神经元结构及nNOS的表达。方法采用双侧颈总动脉结扎法制备慢性前脑缺血动物模型,40只老龄大鼠随机分为假手术组(S)、模型组(M)。应用水迷宫、透射电镜及免疫组化方法对2组大鼠学习记忆、神经元结构、nNOS表达进行观察。结果与假手术组比较,大鼠水迷宫学习记忆能力在造模2个月后差异有统计学意义(P<0.05),大鼠海马神经元在造模后变性水肿明显,大鼠海马及颞叶皮层nNOS在造模2个月后表达增加(P<0.05)。结论海马及颞叶皮层nNOS表达增加,神经元变性,可能导致血管性痴呆大鼠学习记忆障碍。

Objective To observe cognitive function and neurons of hippocampus histomorphology and the expressions of neuronal Nitricoxi-desynthase(nNOS) positive cells in vascular dementia(VD) rats.Methods 40 healthy 12～14 month-old Wister rats were randomly divided into 2 groups,Model rats of chronic forebrain ischemia were subjected to permanent bilateral common carotid arteries ligation for 2 months.Morris water maze was used to test the cognitive function of these rats.We observed neuron histomorphology in virtue of transmission electron microscope;nNOS positive cells were observed through immunohisto-chemistry technique.Results By comparison with sham operated group,the learning and memory abilities of model rats were obviously impaired(P<0.05).Neurons of hippocampus were dropsy and denaturalization significantly.nNOS positive neurons increased in hippocampal and temporal cortex (P<0.05).Conclusion nNOS positive neurons increasing and neurons dropsy may induce the impediment of learning and memory.