慢性癫痫模型大鼠脑谷氨酸神经元的变化

目的　探讨谷氨酸在戊四唑 (PTZ)化学点燃癫痫模型中的作用。方法　实验采用戊四唑点燃癫痫大鼠 ,随机分为对照组和模型组。模型组按点燃进程 ,又随机分为Ⅰ级组、Ⅲ级组、Ⅴ级组和V级后 2 4小时组。运用免疫组织化学方法和图像分析技术 ,对PTZ点燃各发作级别大鼠海马结构和颞叶皮质部位的谷氨酸 (Glu)神经元的变化作一动态观察。结果　PTZ点燃癫痫大鼠 ,Ⅲ级组和Ⅴ级组与对照组相比 ,Glu免疫反应 (Glu IR)阳性神经元数目显著性增加 ,平均光密度 (AOD)值升高 ;而Ⅴ级组与Ⅲ级组相比 ,相应部位各观察值有所下降 ,Ⅴ级后 2 4小时组恢复到对照组水平。结论　PTZ点燃癫痫模型中 ,随着点燃级别的进展 ,谷氨酸表达呈现先增加后减少的趋势 ;可见谷氨酸导致癫痫发作可能是由于其早期胞内合成增加、后期胞外大量释放的结果

Alteration of Glutamate Neurons in Rat Brain of the Chronic Epilepsic Model

Objective To explore the role of glutamate in the pentylenetetrozal kindling model.Methods By pentylenetetrazol kindling in chemical method, the chronic epilepsy model was built. The rats were divided into control group and experimental group. The experimental group included Ⅰ-Grade group、Ⅲ-Grade group、V-Grade group and V-Grade stop 24h group. With the immunohistochemical method and the image analyzing system, the changes of glutamate immunoreactive positive cells in the hippocampus formation and temporal cortex of PTZ kindling rat were observed at different stages. Results In the epilepsic rats of pentylenetetrazol-kindling, the numbers of Glu immunoreactive positive cells(GIPC) and the average optical densities(AOD) of the Ⅲ-Grade group and V-Grade group were increased in the hippocampal formation and temproal cortex compared with control group. On the other hand, compared with Ⅲ-Grade group, numbers of GIPC and AOD were decreased in corresponding regions in the V-Grade group. The numbers of GIPC and AOD in V-Grade stop 24h group were decreased to the level of the control group. Conclusions In the progress of kindling, the expression of Glu increased first, then decreased gradually, which indicates that the increase of glutamate synthesis at first stage inside the cell and later the increased releasing out of cell maybe one of the reasons of epilesic seizure by PTZ kindling.