【摘要】 强直电刺激诱发大鼠急、慢性在体和离体脑片癫疒间模型。观察癫疒间电活动的突触可塑性以及癫疒间发作的行为表达特征。结果表明 :慢性癫疒间 大鼠原发性湿狗样抖的频率先增加后减少及潜伏期逐步缩短 ,并相继出现继发性湿狗样抖和“点燃”效应 ,称之为行为改变的可塑性 ,即“长时程”效应 ;急性在体癫疒间模型上反复强直电刺激海马 ,颞叶新皮质区细胞外场电位原发性后放的潜伏期逐渐缩短及幅度逐级增大 ,此效应在脑室内微量注射东莨菪碱后逐渐消失 ;离体脑片上强直电刺激海马 Schaeffer侧枝 ,CA1神经元膜电位原发性后放电及阵发性爆发放电的潜伏期明显缩短 ,表现为突触传递的“长时程增强”。推测癫疒间发作行为的可塑性变化可能是复杂神经网络多级突触传递长时程效应的整体靶行为表现。更多还原

【Abstract】 In order to detect tetanus induced long term synaptic modification and its target behavior expression in rat epilepsy model, we established chronic ( n =55) and acute ( n =10) epilepsy models by delivering repetitive tetanus into hippocampus (HPC) or medial temporal neocortex (MTNC) in rats. Experiments were performed on three models of epilepsy:Tetanus(60 Hz, 2 s, 0.4～0.6 mA) induced chronic and acute epilepsy rats, and “kindling” model on 400 μm thick horizontal rat brain slices containing the hippocampus (HPC) and entorhinal cortex (EC). In chronically epileptic rats, behavioral abnormalities were observed every day, and EEG or depth electrographic seizures were examined at day 0 or before the end of experiments. T 2 Magnetic Resonance Images(T 2 MRI) were used to determine morphological damage and the tip positions of electrode. In acute epilepsy model the HPC or the MTNC electrographes were recorded following each tetanic train into the MTNC or the HPC for about 10 trains. The results were as follows:①66.67%(8/12) HPC stimulated rats and 58.33% (7/12) MTNC stimulated rats exhibited bidirectional modifiable behavioral expression of primary wet dog shakes (WEDS) at its frequency in chronic epilepsy model;②The primary afterdischarges in MTNC electrographes evoked by a series of tetanus into the dorsal HPC exhibited “long term augmentation” at their amplitude and latency in acute epilepsy model;③Shorten latency of primary afterdischarges and bursting in individual CA1 neuron were observed by delivering 3 stimulating trains into Schaeffer collaterals from whole cell recordings in horizontal brain slices. The results indicated that posttetanic augmentation of primary afterdischarges was not only observed at electrographic level, but also expressed at its target behavior in epileptic seizures in rats. It implied the relations between the modification of synaptic transmission in HPC MTNC cerebral neural pathway and epileptogenesis.[更多还原