ETHANOL INHIBITION OF NMDA RECEPTOR MEDIATED RESPONSES

这项研究项目的目的是进一步了解 乙醇（EtOH）的神经元效应，导致急性中毒。 乙醇抑制N-甲基-D-天冬氨酸（NMDA）型谷氨酸的功能 受体。 在迄今为止检查的大多数神经元制备物中，这种抑制 对其他谷氨酸受体具有选择性。 然而，在这方面， 抑制非NMDA、AMPA/红藻氨酸型谷氨酸的功能 在一些动物中， 例 谷氨酸是哺乳动物体内主要的兴奋性神经递质 中枢神经系统，并已牵连到许多中枢神经系统的功能，包括运动 控制，信息存储，处理感官信息， 呼吸控制 乙醇抑制NMDA介导的反应 受体可能有助于其认知障碍和镇静 影响，而抑制其他谷氨酸受体可能有助于 EtOH诱导的麻醉和呼吸抑制。 EtOH的作用机制 对谷氨酸受体的作用尚不清楚。 另外我们 对谷氨酸受体的分子特性知之甚少， 有助于EtOH敏感性。 行为与行为之间的关系 乙醇及其作用对不同中枢神经系统谷氨酸受体的影响 区域也需要进一步调查。 因此， 测试的是：1）不同亚型的NMDA和AMPA/红藻氨酸谷氨酸 受体对EtOH的敏感性不同， 这些不同的受体亚型将显示不同的EtOH敏感性; 2)乙醇影响谷氨酸的特定动力学方面 受体/通道功能，并将抑制单个NMDA的功能 受体/通道。3)乙醇抑制的效力和选择性 谷氨酸受体介导的反应在不同的神经元中不同， 中枢神经系统的领域;实验来测试前两个假设将进行 使用全细胞和单通道膜片钳记录技术， 来自哺乳动物CNS以及人胚胎肾（HEK 293）的神经元 表达特异性重组谷氨酸受体的细胞。 区域 将进行EtOH作用效价和选择性的变异性 采用急性分离的大鼠脑全细胞膜片钳记录 神经元以及来自大鼠的细胞外和全细胞记录 脑切片 有充分的证据表明谷氨酸受体抑制 在急性中毒中起重要作用。 拟议的实验 这将有助于我们了解乙醇影响的分子基础， 这些受体。 这些实验还将揭示大脑中哪些区域 大脑和哪些谷氨酸受体亚型受此影响最大 EtOH的抑制作用。 希望这些会议的结果 实验将为开发治疗方法提供基础， 可以抵消乙醇的一些致醉作用

The aim of the research project is to further our understanding of the neuronal effects of ethanol (EtOH) which contribute to acute intoxication. Ethanol inhibits the function of N-methyl-D-aspartate (NMDA) type glutamate receptors. In most neuronal preparations examined to date, this inhibition is selective with respect to other glutamate receptors. However, inhibition of the function of non-NMDA, AMPA/kainate type glutamate receptors by intoxicating concentrations of EtOH has been observed in some cases. Glutamate is the major excitatory neurotransmitter in the mammalian CNS, and has been implicated in a number of CNS functions including motor control, information storage, processing sensory information and respiratory control. Ethanol inhibition of responses mediated by NMDA receptors probably contributes to its cognitive impairing and sedative effects, while inhibition of other glutamate receptors could contribute to EtOH-induced anesthesia and respiratory depression. The mechanisms of EtOH action on glutamate receptors are not well understood. In addition, we known little about the molecular properties of glutamate receptors which contribute to EtOH sensitivity. The relationship between the behavioral effects of EtOH and EtOH actions on glutamate receptors in different CNS regions also requires further investigation. Thus the hypotheses to be tested are: 1) That different subtypes of NMDA and AMPA/kainate glutamate receptors are differentially sensitive to EtOH, and that neurons containing these different receptor subtypes will show differential EtOH sensitivity; 2) That EtOH affects specific kinetic aspects of glutamate receptor/channel function and will inhibit the function of single NMDA receptor/channels.; 3) That the potency and selectivity of EtOH inhibition of glutamate receptor-mediated responses differs in neurons from different areas of CNS; Experiments to test the first two hypotheses will be carried out using whole-cell and single channel patch clamp recording techniques in neurons from mammalian CNS as well as human embryonic kidney (HEK 293) cells expressing specific recombinant glutamate receptors. Regional variability n the potency and selectivity of EtOH actions will be performed using whole-cell patch-clamp recording from acutely isolated rat brain neurons as well as from extracellular and whole-cell recording from rat brain slices. There is ample evidence that glutamate receptor inhibition plays an important role in acute intoxication. The proposed experiments will contribute to our knowledge of the molecular basis of EtOH effects on these receptors. These experiments will also reveal which regions of the brain and which glutamate receptor subtypes are most affected by this inhibitory action of EtOH. It is hoped that the outcome of these experiments will provide a basis for the development of treatments which can counteract some of the intoxicating effects of EtOH.