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.
Sheng Li Xue Bao. 2014 Apr 25;66(2):118-28.
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.
癫痫在临床上对认知功能有抑制作用，但它是否与癫痫发生相关尚不清楚。由于癫痫棘波是颞叶癫痫（TLE）的特征，本研究旨在分析癫痫发生过程中散发性棘波（SSs）对θ节律的瞬时影响。在四只经毛果芸香碱注射的大鼠探索过程中，记录其CA1区的局部场电位（LFPs），并在SSs周围以及无SS的延长时间段（均作为实验）和注射前（对照）全局估计θ相位稳定性和功率。最后，借助CA1网络的简化动力学模型，通过改变平均兴奋性和抑制性突触增益值（包括慢速和快速抑制回路）来模拟LFPs，然后在几种情况下评估θ相位稳定性。研究发现，SSs对θ节律可能具有瞬时和持续的负面影响，这可能取决于导致癫痫的时间进程，早期比后期更剧烈，但即使在潜伏期，θ功率也很强。模拟部分表明，与SSs发生伴随的突触失衡可能与θ相位稳定性的动力学有关。结果表明，SSs可能对认知节律具有持续的负面影响，且这些影响在癫痫发生过程中可能会改变，从而导致认知功能障碍。
