ETHANOL DISCRIMINATION AND G PROTEIN COUPLING IN BRAIN

酒精的歧视性刺激特性可能会导致其在人类中的滥用和成瘾。酒精辨别的动物模型表明，5-羟色胺受体，包括G/I/O偶联的5-羟色胺/Lb/D受体，参与了酒精的辨别刺激特性。这项初步研究的主要假设是，大鼠对乙醇的辨别能力的获得与5-羟色胺/L受体活性的变化有关。我们实验室已经开发出一种技术，通过激动剂刺激的[35S]GTP-GammaS放射自显影在组织切片上测量受体偶联G蛋白的活性。这项技术使得G蛋白偶联受体的生化活性能够以高度的解剖分辨率进行量化。这种方法非常适合于研究获得乙醇歧视对5-HT1受体偶联G蛋白活性的影响。放射自显影观察到5-HT1受体偶联G蛋白活性变化的区域将被解剖，并将使用激动剂刺激的[35S]GTP-GammaS结合和膜上的受体结合进行更定量的生化和药理学分析。这一方法结合了行为药理学、神经解剖学和信号转导生物化学，可能阐明5-HTL受体在酒精辨别发展中的神经适应作用。这一试点项目直接解决了该中心关于乙醇歧视性刺激效应潜在的可能细胞机制的目标。它将提供重要的试点数据，以补充中心项目3中进行的研究，并为格兰特博士开展的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.