ANESTHETIC ACTION ON NEUROTRANSMITTER RESPONSES

本项目将研究类固醇麻醉剂对 传输器-门控膜通道。实验是设计的 以确定类固醇与受体结合的位置，以及 定义功能效应的调节机制(S)。 拟议工作的主要焦点是γ-氨基丁酸。 A型受体(GABA-A受体)，已被认为是一种 包括类固醇在内的全身麻醉药的主要作用部位。已定义 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来操纵 表达的亚基的结构，以定义GABA-A的区域 麻醉作用所需的受体亚基。互补性工作 将使用药理学和生物物理方法来检查 麻醉作用的机制。稳定表达的克隆性细胞系 高水平的GABA-A受体将被产生用于 生理生化研究。GABA-A的研究进展 麻醉剂的比较数据将扩大受体的范围 对大脑主要尼古丁受体的作用，稳定表达于非 神经细胞。最后，静脉麻醉药的作用 戊巴比妥和异丙酚将与类固醇在 这些实验。这些结果应该会让我们深入了解 类固醇麻醉剂作用于一个分子靶点的机制， GABA-A受体。与本报告中获得的其他数据的比较 项目和计划作为一个整体将表明影响的范围 哪些麻醉药对几种已识别的膜通道有作用 参与突触传递。此信息是必需的 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.