GLUTAMATE-GATED CHANNELS IN CENTRAL & PERIPHERAL NEURONS

中环谷氨酸门控通道

• 批准号: 6187870
• 负责人: James E Huettner
• 金额: $ 21.39万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-07-01 至 2002-04-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6187870
• 关键词: calcium flux; dizocilpine; glutamate receptor; glutamates; hippocampus; kainate; laboratory rat; neural transmission; neurons; neuropharmacology; receptor expression; synapses; tetrodotoxin; tissue /cell culture; voltage /patch clamp

The long term objective of my work is to provide a better understanding of synaptic transmission by studying the operation of NMDA, AMPA, and kainate receptors, which form ion channels gated by the neurotransmitter glutamate. Another major goal is to uncover properties of these receptors that may allow for clinical intervention to prevent excitotoxic cell death. The experiments outlined in this proposal focus on the functional properties of kainate receptors. This glutamate receptor subtype is thought to regulate neuronal excitability and may contribute to excitotoxicity under certain conditions; but, currently much less is known about kainate receptors than about NMDA and AMPA receptors. Patch clamp techniques will be used to record the whole-cell add single channel currents evoked by excitatory amino acids in isolated neurons that express native glutamate receptors, and in heterologous cells that express cloned glutamate receptor subunits. Kainate receptors will be characterized with respect to their agonist and antagonist pharmacology, desensitization properties, current-voltage relations, relative permeability to calcium and monovalent ions, and susceptibility to modulation. For experiments on CNS neurons, NMDA and AMRA receptors will be blocked with the non- competitive antagonists MK-801 and GYKI 53655, respectively. A second major aim of this study is to test the hypothesis that kainate receptors regulate synaptic transmission. The action of kainate initially will be studied on synapses formed by hippocampal neurons grown in microcultures. In preliminary experiments, the agonists kainate and domoate have been shown to inhibit both excitatory and inhibitory synapses. The possible mechanisms that may underlie this inhibition will be examined in detail. We will seek to establish whether this action involves pre or postsynaptic kainate receptors and whether they are identical to the receptors that mediate kainate currents in these cells. In addition, we will seek to determine the conditions under which kainate receptors may be activated by the endogenous agonist, glutamate.

我工作的长期目标是让人们更好地了解 通过研究 NMDA、AMPA 和红藻氨酸的运作来研究突触传递 受体，形成由神经递质门控的离子通道 谷氨酸。另一个主要目标是揭示这些受体的特性 这可能允许临床干预以防止兴奋性毒性细胞 死亡。本提案中概述的实验重点关注功能 红藻氨酸受体的特性。这种谷氨酸受体亚型是 被认为可以调节神经元的兴奋性，并可能有助于 某些条件下的兴奋性毒性；但是，目前所知甚少 对红藻氨酸受体的影响要大于对 NMDA 和 AMPA 受体的影响。膜片钳 技术将用于记录全细胞添加单通道 表达的孤立神经元中兴奋性氨基酸引起的电流 天然谷氨酸受体，以及表达克隆的异源细胞 谷氨酸受体亚基。红藻氨酸受体的特征在于 关于其激动剂和拮抗剂药理学、脱敏 特性、电流-电压关系、钙相对渗透性 和单价离子，以及对调制的敏感性。对于实验 CNS 神经元、NMDA 和 AMRA 受体将被非- 竞争性拮抗剂分别是 MK-801 和 GYKI 53655。 本研究的第二个主要目的是检验红藻氨酸盐的假设 受体调节突触传递。红藻氨酸最初的作用 将研究由海马神经元形成的突触 微培养物。在初步实验中，激动剂红藻氨酸和 多莫酸已被证明可以抑制兴奋性和抑制性 突触。这种抑制作用的可能机制将是 进行详细检查。我们将寻求确定这一行动是否 涉及突触前或突触后红藻氨酸受体以及它们是否是 与这些细胞中介导红藻氨酸电流的受体相同。 此外，我们将设法确定红藻氨酸在什么条件下 受体可以被内源性激动剂谷氨酸激活。