血管性痴呆大鼠的记忆行为改变与突触结构参数的关系

目的：研究大鼠在慢性脑灌注不足状态下的记忆行为改变以及大脑皮层和海马的突触结构参数改变，探讨记忆行为改变和突触结构参数的关系。方法：采用老年大鼠持久双侧颈总动脉结扎造成慢性脑缺血动物模型，分为正常对照组，缺血2月组，缺血4月组，电脑控制穿梭箱系统观察大鼠记忆行为改变，电镜下观察突触超微结构改变，应用体视学方法和图像分析，对突触结构参数（突触数密度，突触活性带长度，圆盘面积、表面密度）进行分析，并分析两者关系，结果：电脑控制穿梭箱系统观察大鼠主动回避反应（AAR）及被动回避反应（PAR）在缺血2月及4月组均下降，皮层及海马在缺血2月组，缺血4月组突触数密度（Nv)均明显下降，海马在缺血2月组，缺血4月组突触活性带长度（L），突触连接带圆面积（S）及突触表面密度（Sv)均下降，皮层在缺血2月组，缺血4月组未见明显改变。结论：在慢性脑灌注不足状态下的突触数密度下降，突触活性长度减小与记忆行为改变有关。

Relationship of memory behaviors and changes of synapse structure in vascular dementia rats

Objective To explore the relationship of the changes of memory behavior and the of changes of the parameter of synapse structure in the brain cortex and hippocampus of chronic cerebral hypoperfusion rats Methods Chronic cerebral hypoperfusion rat model was established by ligating bilateral common carotid arteries of the old rats (over 12 months) The rats were divided into 3 groups, normal, 2 months ischemia, and 4 months ischemia groups The memory behavior changes were observed with a computerized shuttle training case The ultrastucture of synapse were observed with electron microscopy for the number density, length of activity cord, area of synapses disk, surface density of the synapse, and the results were analyzed with stereology and image analyses The relationship between the behavior and the ultrastructure were studied Results Active avoidance response (AAR) and passive avoidance response (PAR) were decreased in the 2 months ischemia group and the 4 months ischemia group The number density (Nv) of the synapses in the brain cortex and hippocampus were reduced in the 2 months ischemia group and the 4 months ischemia group The length of activity cord (L), the area of synapses disk (S), the area density (Sv) in the hippocampus decreased in the 2 and 4 months ischemia group, and those in the brain cortex did not change in the 2 groups Conclusion The decrease of the number density (Nv) and the length of activity cord (L) of synapses in the chronic cerebral hypoperfusion is related to the memory behavior changes