ENDOGENOUS REGULATORS OF GLUTAMATE-ACTIVATED CHANNELS

对许多神经精神障碍的基本理解集中在 突触作为疾病过程中的关键部位;这导致了几个 设计成功的治疗策略的例子。 在神经学和 在精神病学中，大部分的重点都放在了儿茶酚胺途径上， 然而，越来越明显的是，兴奋性氨基酸作为 神经递质和神经调质也起关键的生理作用。 L-谷氨酸激活几种受体亚型，包括N-甲基-D- 天冬氨酸（NMDA）受体，并且是许多神经元中的主要兴奋性递质。 包括边缘系统在内的大脑区域。 NMDA受体最近 已经证明，在这些神经元中， 突触 这种递质系统与神经退行性疾病有关， 疾病如亨廷顿氏病和阿尔茨海默氏病， 在学习和记忆方面。 最近的研究，特别是 NMDA受体/通道，表明谷氨酸激活的受体和离子 通道具有复杂的药理学，包括几个调节位点 其显著影响受体/通道复合物的功能; 内源性和外源性药物，包括精神活性药物， 苯环利定（PCP）作用于这些调节位点。 然而， 已知的结构或详细的生理机制，这些 配体门控离子通道，因此能够操纵这个系统 目前在治疗上是有限的。 本项目的长期目标是将这些功能联系起来 受体及其结构的调节位点;这种方法 应该允许设计更有效的治疗剂以及 引导分子生物学方法对这些受体。 的目标 该建议是详细研究已知的内源性调节剂， NMDA通道作为了解通道功能的一步。 的 重点将放在两个重要的，未解决的方面，谷氨酸受体 功能：1. NMDA通道的转换调节机制 包括锌的金属离子;和2. NMDA通道的动力学特性 由突触刺激引起。 将使用两种制备液：一级 啮齿动物海马体的分离培养物，和注射的爪蟾卵母细胞 从大鼠海马中纯化poly（A）+ mRNA。 单通道和 将使用电压钳电生理学方法。 激动剂门控 通道将被外源性应用的激动剂激活;以及 海马单个突触前神经元的激活 准备. 预计这些结果将提供重要的新的 谷氨酸受体的功能和调节信息 在CNS。

A basic understanding of many neuropsychiatric disorders has focused on the synapse as a critical site in the disease process; this has led in several examples to design of successful therapeutic strategies. In neurology and psychiatry, much of this emphasis has been on the catecholamine pathways, however it is increasing apparent that excitatory amino acids acting as neurotransmitters and neuromodulators also play key physiological roles. L-glutamate activates several receptor subtypes including the N-methyl-D- aspartate (NMDA) receptor, and is the major excitatory transmitter in many brain regions including the limbic system. The NMDA receptor has recently been shown to underlie a slow excitatory postsynaptic potential at these synapses. This transmitter system has been implicated in neurodegenerative diseases such as Huntington's and Alzheimer's disease, in ischemic brain injury, and in learning and memory. Recent studies, particularly of the NMDA receptor/channel, suggest that glutamate-activated receptors and ion channels have a complex pharmacology including several modulatory sites which dramatically influence the function of the receptor/channel complex; both endogenous and exogenous agents including psychoactive drugs such as phencyclidine (PCP) act on these modulatory sites. However, little is known of the structure or detailed physiological mechanisms of these ligand-gated ion channels, thus the ability to manipulate this system therapeutically is presently limited. The long range goal of this project is relate the function of these receptors and their modulatory sites to their structure; this approach should allow the design of more effective therapeutic agents as well as guide molecular biological approaches to these receptors. The objective of this proposal is to examine in detail a known endogenous regulator of the NMDA channel as a step toward an understanding of channel function. The focus will be on two important, unresolved aspects of glutamate receptor functions: 1. the mechanism of NMDA channel regulation by transition metal ions including zinc; and 2. the kinetic properties of NMDA channels evoked by synaptic stimulation. Two preparations will be used: primary dissociated cultures of rodent hippocampus, and Xenopus oocytes injected with poly (A) + mRNA purified from rat hippocampus. Single channel and voltage clamp electrophysiological methods will be used. Agonist-gated channels will be activated by exogenously applied agonists; as well as by activation of single presynaptic neurons in the cultures hippocampal preparation. It is expected that these results will provide important new information concerning the function and regulation of glutamate receptors in the CNS.