电刺激小脑顶核对HIBD新生大鼠超微结构及突触素表达的影响

Influnce of fastigial nucleus electric stimulation on synaptic ultrastructure and synaptophysin expression in hippocampus of neonatal rat

目的探讨电刺激对缺氧缺血性脑损伤(HIBD)新生大鼠海马CA1区突触超微结构和突触素表达的影响。方法按Rice法制作HIBD新生SD大鼠模型,共计120只,随机分为电刺激组和模型组,同时设假手术对照组(简称对照组)60只。各组术后又按3、7、14、21d随机分为4组。电刺激组大鼠于术后第2d开始给予电刺激,刺激结束后用透射电镜(TEM)观察各组3、7、14、21d海马突触超微结构,免疫组化和图像分析技术检测p38的表达。结果与对照组比较模型组突触数量较少,突触间隙增宽,突触囊泡减少,电刺激组与同时间模型组比较突触间隙较清楚,突触囊泡较多,线粒体数量有所增加至第21d时突触超微结构与对照组相比无明显差异。电刺激组海马CA1区突触素校正光密度值(COD)3d与模型组相比有升高但无统计学意义(P>0.05),14、21d突触素COD值与模型组相比表达升高且具有统计学意义(P<0.05),且21d时与对照组相比表达升高且具有统计学意义(P<0.05)。结论电刺激可减轻缺氧缺血脑损伤后突触超微结构的损伤、促进突触的重建。

Objective To observe the Influnce of electric stinulation on synaptic ultrastructure and the synaptophysin expression（p38）in hippocampal CA1 area after hypoxia-ischemic brain damage（HIBD）in neonatal rats.Methods The rat model of HIBD was made by the method of Rice in 120 SD rats,and divided randomly into 2 groups：the electric stinulation group,model group.Another 60 rats underwent sham-operation as control.According to the time of 3 day,7day,14day,21day,the three groups were divided randomly into 4 groups.From the second day after HIBD,the rats of the electric stinulation group were stimulated.The hippocampal ultrastructure was observed with electron microscope and the p38 expression was detected immunohistochemically at 3 day,7day,14day,21day in rats.Results The ultrastructure of hippocampus CA1 neuron in the model group were distorted as compared with that in the electric stinulation group and control group.The corrected opticaldensities（COD）of immunoreactive products of the hippocampal p38 were significantly decreased in model group as compared with electric stinulation group at 14d,21d（P0.05）.There were no marked difference of immunohistochemically reactived COD of p38 among the three groups at 3d.（P0.05）.Conclusions Electric stinulation could improve the synaptic reconstruction and reduce the ultrastructural damage induced by hypoxic-ischemia.