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匹罗卡品颞叶癫痫大鼠模型中尖波对theta节律的抑制作用

葛曼玲, 郭宝强, 陈雪, 孙英, 陈盛华, 郑颖, 张惠娟, 孙伟

河北工业大学电磁场与电器可靠性省部共建重点实验室，电气工程学院，天津300130；首都医科大学宣武医院神经生理学研究室，北京 100053

摘要

癫痫会降低患者的认知能力是常见的临床现象，但这是否与癫痫发生过程等因素有关尚不清楚。尖波是颞叶癫痫的主要特征，本文应用脑深部记录研究了癫痫发生过程中的散发性尖波(sporadic spikes, SSs)对认知节律theta的影响。实验记录4只注射匹罗卡品导致癫痫发生的大鼠在嗅行(exploration)时的CA1脑区的局部场电位(local field potentials, LFPs)，计算癫痫发生过程的早期和晚期有尖波和无尖波期间theta节律的相位稳定规模和能量，并与注射前对照进行对比。应用混合动力学模型，改变CA1网络的平均兴奋性和抑制性(分别包括慢树突抑制回路和快胞体抑制回路)突触增益，仿真有尖波和无尖波的发作间期CA1区场电位，并据此计算theta节律的相位稳定规模。结果显示，癫痫尖波对theta节律的抑制作用既是短暂的也是持续的，但随癫痫发生过程而变化，早期作用强烈，晚期则平缓，但即便在早期也有很强的theta节律。仿真结果部分地证明了伴随癫痫尖波而出现的突触不平衡可能与theta相位稳定规模动态变化的规律有关。以上结果提示，癫痫尖波对theta节律的抑制影响是永久性的，与癫痫发生过程有关。

关键词： 电生理学; 癫痫; 海马CA1区; 认知

分类号：Q42

[Inhibitory effects of epileptic spikes on theta rhythm in rat pilocarpine model of temporal lobe epilepsy.] [Article in Chinese]

GE Man-Ling, GUO Bao-Qiang, CHEN Xue, SUN Ying, CHEN Sheng-Hua, ZHENG Ying, ZHANG Hui-Juan, SUN Wei

The Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability, Department of Electrical Engineering, Hebei University of Technology, Tianjin 300130, China； Department of Neurophysiology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China

Abstract

Epilepsy clinically has an inhibitory impact on cognitive function, but whether it is associated with epileptogenesis is unclear. Since the epileptic spike characterizes temporal lobe epilepsy (TLE), the present study was aimed to analyze the transient effects of sporadic spikes (SSs) on theta rhythm during epileptogenesis. The local field potentials (LFPs) were recorded in CA1 area in four rats with the pilocarpine injections during exploration, and theta phase stability and power were globally estimated around SSs, also during prolonged period without SS (both as experiments) as well as pre-injections (control). Finally, the LFPs were simulated by changing the average excitatory and inhibitory synaptic gain values (including slow and fast inhibition loops) with the help of simplified dynamical model of CA1 networks, and then theta phase stability was evaluated in several cases. It was found that the SSs could have negative impacts on theta rhythm both transiently and persistently, which may be dependent on the temporal courses leading to epilepsy, being acuter in early stage than later stage, but even in latent stage, theta power was strong. The simulations partly demonstrated that the synaptic imbalance concomitant with the occurrence of SSs might be related to the dynamics of theta phase stability. The results indicate that the SSs might have persistent negative impacts on the cognition rhythm, and the effects might alter during epileptogenesis, leading to the cognitive dysfunction.

Key words: Electrophysiology; epilepsy; hippocampal CA1 region; cognition

收稿日期：2013-08-02　　录用日期：2013-11-13

通讯作者：葛曼玲　　E-mail: mlge@eyou.com

引用本文：

葛曼玲, 郭宝强, 陈雪, 孙英, 陈盛华, 郑颖, 张惠娟, 孙伟. 匹罗卡品颞叶癫痫大鼠模型中尖波对theta节律的抑制作用[J]. 生理学报 2014; 66 (2): 118-128.

GE Man-Ling, GUO Bao-Qiang, CHEN Xue, SUN Ying, CHEN Sheng-Hua, ZHENG Ying, ZHANG Hui-Juan, SUN Wei. [Inhibitory effects of epileptic spikes on theta rhythm in rat pilocarpine model of temporal lobe epilepsy.] [Article in Chinese]. Acta Physiol Sin 2014; 66 (2): 118-128 (in Chinese with English abstract).