Neuroanotomical changes influencing glutamate in seizure foci

谷氨酸是一种强有力的兴奋性神经递质。高水平的 突触释放的谷氨酸可导致神经元过度兴奋和 癫痫发作以及随之而来的神经元死亡。细胞外(ECF) 体内透析证实谷氨酸积聚。 伴有海马区的颞叶癫痫患者的海马区 硬化症。这个项目研究了这种现象背后的细胞机制。 颞叶高浓度谷氨酸释放的分析 通过手术切除了颞叶组织。两种潜在的机制将 被调查。(1)缺陷导致ECF谷氨酸增加 谷氨酸(GLU)转运体功能和/或(2)线粒体缺陷 导致能量代谢受损的功能。GLU的作用 转运蛋白的研究将通过检测其在 用高倍镜免疫组织化学方法检测致痫颞叶 原位杂交、Northern和Western印迹分析以及 定量电子显微镜免疫细胞化学。传送器 功能将通过检查GLU摄取和释放来评估 癫痫灶的原代星形胶质细胞培养，将通过 原代培养星形胶质细胞摄取和释放GLU的检测 癫痫灶，以及分子生物学引起的膜电流 技巧。线粒体功能缺陷将通过以下方法进行研究 评估线粒体密度及其解剖病理 特别是在高海拔地区寻找这种病理的证据 谷氨酸能活动(谷氨酸突触)。瑕疵的贡献 从线粒体代谢到兴奋性氨基酸代谢： 谷氨酸脱氢酶、磷酸激活的谷氨酰胺酶和谷氨酸 合成酶。这些组织研究以及体内和体外研究 同一患者的谷氨酸/谷氨酰胺水平和能量代谢 在项目1和2中将提供谷氨酸能的详细评估 在颞叶癫痫中发挥作用，从而为更好地 这些患者的诊断和处理以及对新的 药物治疗干预。

Glutamate is a potent excitatory neurotransmitter. High levels of glutamate released at synapses can caused neuronal hyperexcitability and seizures as well as consequent neuronal death. Extracellular (ECF) glutamate accumulation has been demonstrated by in vivo dialysis in the hippocampi of patients with temporal lobe epilepsy with hippocampal sclerosis. This project examines the cellular mechanisms underlying this glutamate release at high concentration in the temporal lobe by analysis of surgically removed temporal lobe tissue. Two potential mechanisms will be investigated. (1) Increase in ECF glutamate results from defective glutamate (GLU) transporter function, and/or (2) defective mitochondrial function resulting in impaired energy metabolism. The role of GLU transporters will be studied by examining its expression in the epileptogenic temporal lobe by high microscopic immunohistochemistry, in situ hybridization and Northern and Western blot analysis as well as quantitative electron microscopic immunocytochemistry. Transporter function will be assessed by examining GLU uptake and release in primary astrocyte cultures from seizure foci, as will be assessed by examining GLU uptake and release in primary astrocyte cultures from seizure foci, as well as membrane currents due to molecular biological techniques. Defects in mitochondrial function will be studied by evaluating mitochondrial densities and their anatomical pathology, in particular looking for evidence of such pathology in regions of high glutamatergic activity (glutamate synapses). The contribution of defective mitochondrial metabolism to excitatory amino acid metabolism: glutamate dehydrogenase, phosphate activated glutaminase and glutamate synthatase. These tissue studies together with in vivo and ex vivo studies of glutamate/glutamine levels and energy metabolism in the same patients in projects 1 and 2 will provide detailed assessment of glutamatergic function in temporal lobe epilepsy, thereby opening the way to better diagnosis and management of these patients and critical insights to new pharmacotherapeutic interventions.