Neuroanotomical changes influencing glutamate in seizure foci

影响癫痫病灶谷氨酸的神经解剖学变化

• 批准号: 6233748
• 负责人: NIHAL C DE LANEROLLE
• 金额: $ 22.6万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-13 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6233748
• 关键词: aminoacid metabolism; bioenergetics; brain metabolism; glutamate transporter; glutamates; human tissue; immunocytochemistry; mitochondria; neurochemistry; neurotransmitter metabolism; neurotransmitter transport; partial seizure; pathologic process; temporal lobe /cortex disorder

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.

谷氨酸是一种有效的兴奋性神经递质。高水平的 在突触处释放的谷氨酸可引起神经元过度兴奋， 癫痫发作以及随后的神经元死亡。细胞外（ECF） 谷氨酸积累已经通过在小鼠中的体内透析证明。 颞叶癫痫患者的海马CA 1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， 手术切除的颞叶组织两种潜在机制将 追究(1)ECF谷氨酸盐的增加是由于缺陷性 谷氨酸（GLU）转运蛋白功能，和/或（2）线粒体缺陷 导致能量代谢受损的功能。GLU的作用 转运蛋白将通过检查其表达进行研究， 致痫性颞叶高镜免疫组化， 原位杂交和北方和西方印迹分析以及 定量电镜免疫细胞化学。转运蛋白 将通过检查葡萄糖的摄取和释放来评估功能， 来自癫痫灶的原代星形胶质细胞培养物，如将通过 检测了来自人的原代星形胶质细胞培养物中的GLU摄取和释放， 癫痫灶，以及膜电流由于分子生物学 技术.线粒体功能的缺陷将通过 评估线粒体密度及其解剖病理学， 特别是在高血压地区寻找这种病理学的证据。 谷氨酸能活动（谷氨酸突触）。缺陷的贡献 线粒体代谢到兴奋性氨基酸代谢： 谷氨酸脱氢酶、磷酸活化的谷氨酸脱氢酶和谷氨酸 酶。这些组织研究以及体内和离体研究 谷氨酸/谷氨酰胺水平和能量代谢在同一患者 在项目1和2将提供详细的评估， 颞叶癫痫的功能，从而开辟了更好的方式， 这些患者的诊断和管理，以及对新的 药物干预。