痫样放电与海马CA3区神经元死亡的关系

Association of epileptiform activity with neuronal death in the CA3 subfield of the hippocampus following focally evoked limbic seizures

目的 定量研究大鼠杏仁核注射海人酸所致的痫样放电与海马ＣＡ３区神经元死亡的关系。方法 以深部脑电图监 测Ⅳ级痫样放电的持续时间，以ＨＥ染色观察记数存活神经元，以ＴＵＮＥＬ染色观察记数凋亡神经元。通过相邻切片的 ＨＥ染色和ＴＵＮＥＬ染色估算坏死神经元数。结果 痫样放电导致凋亡为主的，伴有坏死的ＣＡ３神经元死亡；放电的持 续时间越长，神经元存活数越少，坏死和凋亡的神经元数目越多。结论 随着Ⅳ级放电持续时间的延长，海马ＣＡ３存活 细胞呈剂量依赖性地减少，坏死和凋亡细胞都呈剂量依赖性地增加。

Objective To investigate the relationnship between epileptiform activity and cell death in the CA3 subfield of the hippocampus following focally evoked limbic seizures through a quantitative study. Methods Wistar rats used in this study received intra-amygdaloid injection of kainic acid to induce type IV epileptiform activity of different duration with continuous electroencephalographic (EEG) monitoring Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was used to detect apoptotic cells. The number of CA3 neurons survived and TUNEL-positive cells were counted to estimate the number of necrotic cells. Results Epileptiform activity induced cell death in the major form of apoptosis of the cells in CA3 subfield of the hippocampus following focally evoked limbic seizures. The longer the type IV epileptiform activity lasted, the less neurons survived, with consequent increase in the number of both necrotic and apoptotic cells. Conclusion Prolongation of type IV seizures dose-dependently causes increase in apoptotic and necrotic cells in CA3 subfield of the hippocampus.