GLUTAMATE GATED CHANNELS IN CENTRAL & PERIPHERAL NEURONS

我工作的长期目标是更好地了解 通过研究NMDA、AMPA和红藻氨酸盐的运作来研究突触传递 受体，形成由神经递质控制的离子通道 谷氨酸盐。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侧重于功能性 红藻氨酸受体的特性。这种谷氨酸受体亚型是 被认为调节神经元的兴奋性，并可能有助于 在某些条件下的兴奋性毒性;但是，目前知之甚少 而不是NMDA和AMPA受体。膜片钳 技术将用于记录全细胞添加单通道 兴奋性氨基酸诱发的电流在分离的神经元，表达 天然谷氨酸受体，并在异源细胞中表达克隆 谷氨酸受体亚单位红藻氨酸受体的特征在于 关于其激动剂和拮抗剂药理学、脱敏作用 性质，电流-电压关系，钙的相对渗透性 和单价离子以及对调制的敏感性。实验的 CNS神经元、NMDA和AMRA受体将被非- 竞争性拮抗剂MK-801和GYKI 53655。 本研究的第二个主要目的是检验红藻氨酸盐 受体调节突触传递。红藻氨酸的作用最初 将在海马神经元形成的突触上进行研究， 微培养在初步实验中，激动剂红藻氨酸和 已显示domoate抑制兴奋和抑制 突触这种抑制的可能机制将 进行详细检查。我们将试图确定这一行动是否 涉及突触前或突触后红藻氨酸受体，以及它们是否 与这些细胞中介导红藻氨酸电流的受体相同。 此外，我们将寻求确定在何种条件下， 受体可被内源性激动剂谷氨酸激活。

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.