ANESTHETIC ACTION ON NEUROTRANSMITTER RESPONSES

本项目将研究类固醇麻醉剂对 膜通道 实验设计 以确定类固醇结合的受体位点， 定义介导功能效应的机制。 拟议工作的主要重点是γ-氨基丁酸 A型受体（GABA-A受体），其已被提议作为 包括类固醇在内的全身麻醉药的主要作用部位。 定义 亚基的组合将在非神经细胞中表达。 分子生物学技术将被用于操纵 表达的亚基的结构，以定义GABA-A的区域 受体亚单位所需的麻醉作用。 补充工作 将使用药理学和生物物理学方法来检查 麻醉作用的机制。 稳定克隆细胞系表达 将产生更高水平的GABA-A受体， 生理和生化研究。 GABA-A的研究 受体将通过麻醉剂获得的比较数据来扩展 作用于主要的脑烟碱受体，稳定表达在非 神经细胞 最后，静脉麻醉剂的作用 戊巴比妥和丙泊酚将与类固醇进行比较， 这些实验。 研究结果应有助于深入了解 类固醇麻醉剂作用于一个分子靶点的机制， GABA-A受体 与此期间获得的其他数据的比较 项目和整个计划将表明影响的范围 麻醉剂在几个已确定的膜通道上的作用 参与突触传递。此信息是需要的， 更好地理解与麻醉相关的细胞活动。

This project will examine the actions of steroid anesthetics on transmitter-gatedmembrane channels. The experiments are designed to determine the sites on receptors to which the steroids bind, and define the mechanism(s) by which functional effects are mediated. The main focus of the proposed work is the gamma-amino butyric acid type-A receptor (GABA-A receptor), which has been proposed as a major site of action for general anesthetics, including steroids. Defined combinations of subunits will be expressed in non-neural cells. Molecular biological techniques will be used to manipulate the structure of the expressed subunits, to define regions of GABA-A receptor subunits required for anesthetic action. Complementary work will use pharmacological and biophysical approachers to examine the mechanism for anesthetic action. Stable clonal cell lines expressing high levels of GABA-A receptors will be generated for use in physiological and biochemical studies. The studies of GABA-A receptors will be extended by comparative data obtained for anesthetic actions on the major brain nicotinic receptor, stably expressed in non- neural cells. Finally, the actions of the intravenous anesthetics pentobarbital and propofol will be compared to those of steroids in these experiments. The results should lead to insights into the mechanisms by which steroid anesthetics act at one molecular target, the GABA-A receptors. Comparisons with other data obtained in this project and the Program as a whole will indicate the range of effects which anesthetics have on several identified membrane channels involved in synaptic transmission. This information is required for a better understanding of the cellular actions associated with anesthesia.