MEMBRANE PROPERTIES, AMINO ACID RECEPTORS, AND LOCAL CIRCUITS

电生理学研究将在发育中的切片上进行。 人类新皮层检查内在的电生理特性 皮质神经元，兴奋性和抑制性氨基酸的药理学 受体和局部突触回路的特征。 的 拟议的实验将在人类皮层组织上进行手术 因治疗灾难性的儿童癫痫而移除 对于来自 每个病人，最不正常的， 面积和最小异常面积。 组织的相对正常 将根据临床数据评价样本，例如术中 皮质电图（ECoG），正电子发射断层扫描（PET），病理学， 等 实验方法包括：（1）细胞内记录 用电流钳和电压钳技术， 电极，（2）药理学激动剂的浴和微量应用， 拮抗剂，和（3）细胞内染色。 实验将测试 关于灾难性童年的细胞机制的具体假设 癫痫和有关的变化，在新皮层神经生理学，发生在 人类发展 重点分析：（1） 电流诱发的动作电位和棘波爆发及其潜在的 电压依赖性Na+和Ca 2+电导，（2）N-甲基-D-天冬氨酸 （3）GABA介导的突触抑制，和（4）局部 兴奋回路 每一个具体目标都包括关于 灾难性儿童癫痫的潜在细胞机制， 人类皮层神经元电生理学的发育变化。 特别强调，特别是在赠款开始时，将 旨在验证癫痫和/或发育性癫痫 人类大脑新皮层的变化包括数量或性质的改变 NMDA受体或减少GABAA介导的抑制。 长期 研究将确定局部兴奋回路的可能变化， 新皮质锥体细胞 大脑皮层解剖结构的改变 神经元，可能与癫痫发生和/或发展有关， 将在细胞内用生物胞素染色的神经元中进行检查。 的 目的是提供关于电生理学的基本新信息， 人类皮层神经元的特性，这些特性如何变化 以及它们如何参与和/或改变， 灾难性的儿童癫痫

Electrophysiological studies will be conducted on slices from developing human neocortex to examine intrinsic electrophysiological properties of cortical neurons, the pharmacology of excitatory and inhibitory amino acid receptors, and the characteristics of local synaptic circuits. The proposed experiments will be performed on human cortical tissue surgically removed for treatment of catastrophic childhood epilepsy. For tissue from each patient, direct comparisons will be made between the most abnormal area and the least abnormal area. The relative normality of the tissue samples will be evaluated from clinical data, such as intraoperative electrocorticography (ECoG), positron emission tomography (PET), pathology, etc. The experimental methods will include: (1) intracellular recording with current- and voltage-clamp techniques using sharp and patch electrodes, (2) bath and microapplication of pharmacological agonists and antagonists, and (3) intracellular staining. The experiments will test specific hypotheses about the cellular mechanisms of catastrophic childhood epilepsy and about changes in neocortical neurophysiology that occur during human development. Particular emphasis will be on analyses of: (1) current-evoked action potentials and spike bursts and their underlying voltage-dependent Na+ and Ca2+ conductances, (2) N-methyl-D-aspartate (NMDA) receptors, (3) GABA-mediated synaptic inhibition, and (4) local excitatory circuits. Each specific aim includes hypotheses concerning the underlying cellular mechanism(s) of catastrophic childhood epilepsy and developmental changes in the electrophysiology of human cortical neurons. Particular emphasis, especially at the beginning of the grant, will be aimed at testing the hypothesis that epileptogenic and/or developmental changes in human neocortex involve alterations in the number or properties of NMDA receptors or decreases in GABAA-mediated inhibition. Long-term studies will determine possible changes in local excitatory circuits among neocortical pyramidal cells. Alterations in the anatomy of neocortical neurons, which could be associated with epileptogenesis and/or development, will be examined in neurons stained intracellularly with biocytin. The goal is to provide fundamental new information on the electrophysiological characteristics of human cortical neurons, how these properties change during development, and how they are involved in and/or altered during catastrophic childhood epilepsy.