Motor cortex plasticity in temporal lobe epilepsy

项目摘要 癫痫大发作，现在被称为全身强直阵挛发作（GTCS），是最可怕的 因为它们会导致死亡和伤害。反复GTCS是突发性GTCS的主要危险因素。 癫痫意外死亡（SUDEP）是癫痫患者死亡的主要原因。GTCS还 导致骨折和软组织损伤很久以前就知道运动皮层产生这些癫痫发作， 癫痫发作会改变运动皮层然而，细胞和分子机制， 运动皮层的重组尚未被研究。此外，尚不清楚GTCS是否 随后的癫痫发作更加严重。我们认为，GTCS增强了运动皮层的一个子集的兴奋性 锥体神经元通过增强AMPA受体介导的兴奋。我们发现，GluA 1亚单位的 AMPA受体是表达点燃诱导的（5级）GTCS所必需的。我们点燃老鼠， GluA 1亚基AMPA受体及其野生型（WT）同窝仔使用传统的点燃方法。 而WT动物进展为持续惊厥性GTCS（4级和5级），而敲除动物既没有 尽管反复刺激，也没有获得持续的GTCS。此外，2只（WT）动物在 GTCS，而KO动物均未死亡。在目的1中，我们提出了GluA 1亚基的作用的特点， 使用条件性基因敲除小鼠和 海马内红藻氨酸（IHK）和点燃模型的TLE的生化技术。行为性癫痫发作 当完全点燃的动物受到刺激时也变得更加强烈。大脑皮层的体积要大得多 与第3次GTCS后观察到的新皮质激活相比，第8次GTCS期间的激活。运动皮层 细胞计数显示，运动皮层中更多的神经元表达c-fos，以响应第五次GTCS 与第一次GTCS相比。在目标2实验中，我们建议确认和扩展这些发现。我们将 比较点燃时第一次或第五次GTCS时皮层回路活动图和行为癫痫发作 和IHK TLE模型。我们比较了运动皮层锥体神经元的电生理特性， 表达c-fos的神经元与不表达c-fos的周围神经元对GTCS的反应一致， 惊人的差异。表达c-fos的运动皮质锥体神经元更易兴奋， 显示增强的AMPA受体介导的兴奋性突触后电流。在目标3中，我们建议 比较表达c-的2/3层和4/5层锥体神经元的兴奋性和兴奋性传递， 使用膜片钳记录响应于5级点燃癫痫发作的Fos。这些研究开辟了一个新的领域， 癫痫研究，重点是使用新的组合联合收割机， 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.