电刺激构建大鼠皮层网络癫痫的海马细胞电生理特征  

The role of the rat hippocampal cellular electrophysiology in electrogenic cortical epileptic network reorganization

作　　者：汪胜[1] 刘青[1] 邹祖玉[2] 韩丹[1] 

机构地区：[1]武汉大学医学院生理学系,湖北武汉430071 [2]武汉大学医学院病理学与病理生理学系,湖北武汉430071

出　　处：《神经科学通报》2005年第4期257-265,共9页Neuroscience Bulletin

基　　金：supported by grant from the Natural Science Foundation of Hubei Province,China(No.2003ABA123)

摘　　要：本文旨在探讨急性强直电刺激右后背海马(hippocampus,HPC)诱导出现双侧皮层网络癫痫的前背HPC神经元电生理机制。实验共用雄性SD大鼠35只,急性强直电刺激(60Hz,2s,0.4-0.6mA)大鼠右侧后背HPC(a-cute tetanization of the right posterior dorsal hippocampus,ATPDH)诱发癫痫模型。四通道同步记录双侧皮层电图(electroeorticogram,ECoG)或前背HPC深部电图和双侧前背HPC单位放电。结果显示,ATPDH可以引起以下效应:(1)双侧皮层癫痫样电活动起源于同侧HPC单位后放电,继而引起对侧HPC单位后放电,最终形成对侧和同侧皮层电图癫痫发作样电振荡;(2)增强双侧皮层4-10Hz节律性电振荡或诱发双侧HPC100-250Hz电振荡,与此同时双侧HPC神经元均表现为非对称性电活动;(3)双侧HPC神经元锋电位间期(interspike interval,ISI)点呈现非规则性环状分布。同侧HPC爆发式单位放电ISI点分布的环状分层较规则、发生率较高,并与同侧HPC电振荡最大振幅的正弦式波动形成明显的时间对应关系。结果表明:ATPDH可诱导双侧皮层和HPC电图形成癫痫电网络。当皮层或HPC癫痫网络重建过程中,HPC神经元放电具有特征性ISI点环状分布等编码形式。The purpose of the present work was to study hippocampal cellular electrophysiology involved in cortical epileptic networks reorganized by acute tetanization （60 Hz, 2 s, 0.4-0.6 mA） of the right posterior dorsal hippocampus （ATPDH）. Experiments were performed on 35 adult male Sprague-Dawley rats. The ATPDH was used to establish epilepsy model. Four-channel recordings were done simultaneously, two channels for single unit recordings from bilateral hippocampi and other two channels for electrocorticogram （ECoG） or hippocampal electroencephalogram （EEG） recordings on the bilateral sides. The ATPDH bilaterally induced： （1） Epileptic ECoG activities that were originated from single unit afterdischarges of ipsilateral hippocampal neuron, followed by single unit afterdischarges of contralateral hippocampal neuron, finally produced seizure-like oscillations in the contralateral and ipsilateral ECoG. （2） 4-10 Hz rhythmic ECoG oscillations and 100-250 Hz hippocampal EEG oscillations, and asymmetric electrical activities of bilateral hippocampal neurons. （3） The hippocampal neuronal bursting that appeared its interspike interval （ISI） spot distribution in an irregular circular shape. The ipsilateral circular shape ISI distribution was more regular and occurred often, which was time-locked with the sinusoidal pattern of maximum peaks of hippocampal oscillatory trains. The resuhs imply that the epileptic networks are reorganized bilaterally between ECoG and hippocampal EEG by the ATPDH. The hippocampal neuronal firing temporally encodes its information, in particular, the irregular circular shape ISI distribution during epileptic network reorganization.

关 键 词：癫痫电网络 皮层 海马 锋电位间期 强直电刺激 

分 类 号：R742.1[医药卫生—神经病学与精神病学]