戊四氮致()大鼠海马神经元与星形胶质细胞间关系的超微结构观察

Observation of ultrastructure of morphological relationship between neurons and astrocytes in hippocampi of pentylenetetrazol-kindled epileptic rats

目的通过电镜下观察戊四氮（PTZ）点燃大鼠海马神经元、星形胶质细胞之间的超微结构，探寻胶质细胞与神经元之间信息交流的结构基础。方法10只大鼠每日腹腔注射PTZ（35mg／kg）制作点燃大鼠模型，存活3d以记录点燃后大鼠自发性抽搐的次数确保点燃大鼠模型成功。5只大鼠腹腔注射9g/L盐水作为对照组。采用透射电镜，以及抗Cx43标记星形胶质细胞的免疫电镜方法观察PTZ致痫大鼠海马神经元与星形胶质细胞之间的连接结构。结果1．PTZ点燃大鼠海马神经元间的突触连接增多；2．神经元之间、星形胶质细胞之间各自存在缝隙连接；3．星形胶质细胞突起伸入神经元的突触前膜与突触后膜之间，形成突触复合体；4．神经元与星形胶质细胞之间存在Cx43构成的半通道。结论PTZ点燃大鼠海马存在星形胶质细胞突起与突触形成的突触复合体以及缝隙连接、半通道，可能是癫痫大鼠海马神经元、星形胶质细胞之间信息交流的结构基础。

Objective To observe uhrastructure of the morphological relationship between neuron and astro- cytes in hippocampi of pentylenetetrazol （PTZ）-kindled epileptic rats, and to investigate the communicative ways be- tween them. Methods Epilepsy models of 10 kindled rats established by intraperitoneal injection of PTZ[ i. p. ,35 rag/ （kg·d） ] ,assigned as kindled group. Five rats received 9 g/L saline as control group. Three days after being kindled, the ultrastructural relationship between neurons and the astrocytes was observed with transmission electron microscope and Cx43 labelling immuno-electron microscopy. Results 1. Synapses increased in hippocampi of PTZ-kindled epilep- tic rats. 2. Gap junctions were observed between astrocytes and neurons. 3. Astrocytic process extended into the synaptic cleft between pre-synaptic and post-synaptic membranes which formed the synaptic complex. 4. The Cx43-hemichannels existed between astrocytes and neurons. Conclusions In hippocampi of PTZ-kindled epileptic rats, ultrastructure of morphological relationship between neurons and astrocytes includes synaptic complex, gap junctions and hemichannels, which might be communicative forms between neurons and astrocytes.