慢性前脑缺血致痴呆大鼠皮质及皮质下白质区病理学变化的对比研究

目的对比研究慢性前脑缺血致血管性痴呆(VD)大鼠额叶、颞叶皮质、海马及皮质下白质区的病理学变化，探讨血管性痴呆发病的病理基础。方法采用双侧颈总动脉永久结扎方法制备慢性前脑缺血致VD大鼠动物模型；通过常规HE及LFB染色，对比观察缺血后不同时间点大鼠额、颞叶皮质、海马区及皮质下白质的形态学改变；应用HPIAS-1000高清晰彩色病理图文分析系统进行图像分析．检测皮质下白质神经纤维脱失情况。结果HE染色结果显示：缺血1个月时额、颞叶皮质及海马区以锥体细胞缺血的改变为主，逐渐转变为锥体细胞凝固性坏死、变性、脱失及星形胶质细胞增生，少数大鼠额叶出现梗死灶；缺血1个月起实验组大鼠皮质下白质神经纤维疏松、断裂、脱失，且有随缺血时间延长而逐渐加重的倾向；图像分析显示缺血1个月实验组大鼠脑白质神经纤维脱失，出现囊泡样改变并逐渐增重。结论进行性的额、颞叶皮质、海马神经元退变以及皮质下白质损害是VD的病理基础，且白质区的损害要早于皮质。

onstract study of cortex and subcortical white matter neuropathology changes of vascular dementia rats after chronic cerebral ischemia

Objective To constract study on the frontal cortex,temporal lobe and Hippocampus with subcortical white matter neuropathology changes of vascular dementia(VD) rats after chronic ischemia. Methods We adopted the permanent occlusion of bilateral common carotid arteries in Wistar rats to produce the chronic forebrain ischemia; Brain samples with HE and LFB staining from frontal lobe,temporal lobe,hippocampus and the white matter were examined with light microscopic methods at 1, 2, 3 and 4m after the operation;The abnormalities of white matter nerve fibre bundle were quantified with an image-analysis system. Results The pyramidal cells of frontal cortex,temporal lobe and hippocampus appeared ischemic changes, such as pyknosis, denaturation, necrosis and degeneration; small vessels proliferation; the proliferation of gliacytes generally existed to form glial nodes; damages of the nerve fibers and myelin sheath were found in the white matter under the cortical layer. The changes mentioned above became severer with the elapse of time. Conclusion The pyramidal neurons of rats decreased progessively and leukoaraiosis after chronic cerebral hypoperfusion are the basic neuropathology of VD,and the change of white matteris occures ealier.