ETHANOL INHIBITION OF NMDA RECEPTOR MEDIATED RESPONSES

这项研究项目的目的是加深我们对 乙醇(Etoh)对神经元的影响，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 感受器。到目前为止，在大多数被检查的神经元准备中，这种抑制 相对于其他谷氨酸受体是有选择性的。然而， 对非NMDA、AMPA/海人酸型谷氨酸功能的抑制 已经观察到通过酒精中毒浓度的受体在一些 案子。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，并与包括运动在内的许多中枢神经系统功能有关 控制、信息存储、处理感官信息和 呼吸控制。乙醇对NMDA介导的反应的抑制作用 受体可能与其认知损害和镇静作用有关。 影响，而抑制其他谷氨酸受体可能有助于 乙醇诱导的麻醉和呼吸抑制。乙醇的作用机制 谷氨酸受体的作用还不是很清楚。此外，我们 对谷氨酸受体的分子特性知之甚少 有助于提高乙醇敏感性。行为与行为之间的关系 乙醇及其作用对不同中枢谷氨酸受体的影响 各地区还需要进一步调查。因此，假设是 检测的是：1)不同亚型的NMDA和AMPA/海人藻氨酸谷氨酸 受体对乙醇具有不同的敏感性，神经元含有 这些不同的受体亚型将表现出不同的乙醇敏感性； 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性别的神经元中不同 中枢神经系统的区域；将进行验证前两个假设的实验 使用全细胞和单通道膜片钳记录技术 哺乳动物中枢神经系统和人类胚胎肾脏的神经元(HEK 293) 表达特定重组谷氨酸受体的细胞。地区性 将执行乙醇行动的效力和选择性的可变性 急性分离大鼠脑的全细胞膜片钳记录 大鼠神经元以及细胞外和全细胞记录 脑片。有充分的证据表明谷氨酸受体抑制 在急性中毒中起着重要作用。拟议中的实验 将有助于我们对乙醇效应的分子基础的了解 这些受体。这些实验还将揭示大脑中的哪些区域 大脑和哪些谷氨酸受体亚型受此影响最大 乙醇的抑制作用。希望这些活动的结果 实验将为开发治疗方法提供基础 可以抵消乙醇的一些醉人效应。

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.