Motor cortex plasticity in temporal lobe epilepsy

项目总结 大发作，现在被称为全身性强直阵挛发作(GTCS)，是最令人恐惧的 癫痫发作，因为它们会导致死亡和受伤。反复的GTCS是突发事件的主要危险因素 癫痫中的意外死亡(SUDEP)，这是癫痫患者死亡的主要原因。GTCS还 导致骨折和软组织损伤。人们早就知道，运动皮质会产生这些癫痫发作，并且 癫痫发作改变了运动皮质。然而，癫痫诱导的细胞和分子机制 运动皮质的重组还没有研究过。此外，还不知道GTCS是否会使 随后的癫痫发作更严重。我们认为GTCS增强运动皮质的一部分的兴奋性。 增强AMPA受体介导的兴奋性锥体神经元。我们发现GluA1亚基是 AMPA受体是表达点燃诱导的(5级)GTCS所必需的。我们点燃了老鼠，没有 AMPA受体GluA1亚基及其野生型(WT)仔鼠使用传统点燃方法。 而WT动物进展为持续性惊厥GTCS(4级和5级)，但基因敲除动物都没有 尽管反复刺激，但仍未达到或维持GTCS。此外，两只(WT)动物死于 GTCS，而KO动物无一死亡。在目标1中，我们建议表征GluA1亚单位的作用 使用条件基因敲除小鼠和联合应用研究AMPA受体在维持反复GTCSs中的作用 海马海人酸(IHK)和TLE点燃模型的生化技术。行为惊厥 当完全点燃的动物受到刺激时，也会变得更加强烈。皮质的体积要大得多 与第三次GTCS后观察到的新皮质激活相比，GTCS在第8次GTCS期间激活。运动皮质 细胞计数显示，运动皮质中有更多的神经元表达c-fos，以响应第五次GTCS 与第一届GTCS相比。在目标2实验中，我们建议证实和扩展这些发现。我们会的 比较点燃时第一次或第五次GTCS对皮层回路活动图和行为发作的反应 和IHK TLE型号。我们比较了运动皮质锥体神经元的电生理特性 与周围不表达c-fos的神经元反应GTCSs的c-fos表达，并发现 令人惊讶的差异。表达c-fos的运动皮质锥体神经元更具兴奋性， AMPA受体介导的兴奋性突触后电流增强。在目标3中，我们建议 比较2/3层和4/5层锥体神经元表达c-受体的兴奋性和兴奋性传递 使用膜片钳记录对5级点燃发作的反应。这些研究开辟了一个新的领域 癫痫研究，集中在GTCS对新皮质的影响，使用组合组合小说， 最先进的技术。

Project summary Grand mal (great malady) seizures, now called generalized tonic clonic seizures (GTCS), are the most feared seizures because they can cause death and injury. Repeated GTCSs are the leading risk factor for sudden unexpected death in epilepsy (SUDEP), which is a leading cause of death in persons with epilepsy. GTCS also leads to fractures and soft tissue injuries. It is long known that the motor cortex generates these seizures and seizures modify the motor cortex. However, the cellular and molecular mechanisms of seizure-induced reorganization of the motor cortex have not been studied. Furthermore, it is not known whether a GTCS makes subsequent seizures more severe. We propose that GTCS enhance the excitability of a subset of motor cortex pyramidal neurons by enhancing AMPA receptor mediated excitation. We found that GluA1 subunit of the AMPA receptor was essential for expressing kindling-induced (grade 5) GTCS. We kindled mice lacking the GluA1 subunit of AMPA receptors and their wild-type (WT) littermates using traditional kindling methods. Whereas WT animals progressed to sustained convulsive GTCS (grade 4 & 5), but knockout animals neither attained nor sustained GTCS, despite repeated stimulation. Furthermore, two (WT) animals died following GTCS, while none of the KO animals died. In Aim 1, we propose to characterize the role of the GluA1 subunit of AMPA receptors in sustaining repeated GTCSs using a combination of conditional knockout mice and biochemical techniques in intrahippocampal kainate (IHK) and kindling models of TLE. Behavioral seizures also become more intense when fully kindled animals were stimulated. Much larger volume of the cortex was active during the 8th GTCS compared to the neocortical activation observed after the 3rd GTCS. Motor cortex cell counts revealed that many more neurons in the motor cortex expressed c-fos in response to the fifth GTCS compared to the first GTCS. In Aim 2 experiments, we propose to confirm and expand these findings. we will compare cortical circuit activity maps and behavioral seizures in response to the first or fifth GTCS in kindling and IHK TLE models. We compared the electrophysiological properties of motor cortex pyramidal neurons that expressed c-fos in response to GTCSs with those of surrounding neurons that did not express c-fos and found surprising differences. Motor cortex pyramidal neurons expressing c-fos were more excitable and demonstrated enhanced AMPA receptor-mediated excitatory post synaptic currents. In Aim 3, we propose to compare the excitability and excitatory transmission of layer 2/3 and layer 4/5 pyramidal neurons expressing c- fos in response to a grade 5 kindled seizure using patch clamp recordings. These studies open a novel area of epilepsy research, focusing on the effects of GTCS on the neocortex using a combination combine novel, state-of-the-art techniques.