ETHANOL DISCRIMINATION AND G PROTEIN COUPLING IN BRAIN

酒精的鉴别刺激特性可能导致人类滥用和成瘾。酒精辨别的动物模型表明5-羟色胺（5-HT）受体，包括G/i/o偶联的5-HT/lB/D受体，参与介导酒精的辨别刺激特性。提出的初步研究的主要假设是，大鼠获得乙醇识别与5-HT/l受体活性的变化有关。我们的实验室开发了一种技术，通过在组织切片中使用激动剂刺激的[35S]GTPgammaS放射自显影术来测量受体偶联g蛋白活性。该技术允许定量的生化活性的g蛋白偶联受体与高度的解剖分辨率。这种方法非常适合于研究乙醇识别对5-HT1受体偶联g蛋白活性的影响。在放射自显像上观察到5-HT1受体偶联g蛋白活性变化的区域将被解剖，并使用激动剂刺激[35S]GTPgammaS结合和膜上受体结合进行更多的定量生化和药理学分析。该方法将行为药理学与神经解剖学和信号转导生物化学相结合，可能阐明5-HTl受体在乙醇识别发展中的神经适应性作用。该试点项目直接解决了该中心关于乙醇歧视性刺激效应可能的细胞机制的目标。它将提供重要的试点数据，可以补充中心项目3的研究，并为Grant博士进行的R01工作提供信息。

The discriminative stimulus properties of alcohol may contribute to its abuse and addiction potential in humans. Animal models of alcohol discrimination have indicated the involvement of serotonin (5-HT) receptors, including the G/i/o-coupled 5-HT/lB/D receptors, in mediating the discriminative stimulus properties of alcohol. The main hypothesis of the proposed pilot study is that the acquisition of ethanol discrimination in rats is associated with changes in 5-HT/l receptor activity. A technique has been developed in our laboratory, whereby receptor-coupled G-protein activity is measured by agonist-stimulated [35S]GTPgammaS autoradiography in tissue sections. This technique allows quantification of the biochemical activity of G-protein-coupled receptors with a high degree of anatomical resolution. This methodology is ideally suited to the study of the effects of the acquisition of ethanol discrimination on 5-HT1 receptor-coupled G-protein activity. Regions where changes in 5-HT1 receptor-coupled G-protein activity are observed autoradiographically will be dissected, and more quantitative biochemical and pharmacological analysis will be performed using both agonist-stimulated [35S]GTPgammaS binding and receptor binding in membranes. This approach, which combines behavioral pharmacology with neuroanatomy and signal transduction biochemistry, may elucidate the neuroadaptive role of 5-HTl receptors in the development of ethanol discrimination. This pilot project directly addresses the Center aims regarding the possible cellular mechanisms underlying ethanol's discriminative stimulus effects. It will provide import pilot data that can supplement the studies performed in Project 3 of the Center, as well as provide information for the R01 work conducted by Dr. Grant.