PHYSIOLOGICAL ROLE OF MULTIPLE K+ CHANNELS

多个 K 通道的生理作用

• 批准号: 2892132
• 负责人: Ronald M Harris-Warrick
• 金额: $ 25万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-09 至 2000-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2892132
• 关键词: Xenopus; Xenopus oocyte; dopamine; electrophysiology; gene expression; genetic mapping; molecular cloning; neurons; neurophysiology; octopamine; polymerase chain reaction; potassium channel; serotonin; single cell analysis

DESCRIPTION (Adapted from applicant's abstract) : A large number of voltage-sensitive K+ channels are coded by the four genes in the Shaker family. In Drosophila, three of these genes undergo alternative splicing of their mRNA to generate multiple proteins with different biophysical properties. In addition, splice variants of a single gene can interact to form heteromultimeric channels. The physiological roles of this potassium channel diversity are not well understood. It is difficult to associate a particular gene with an ionic current in a cell, and to show how that gene product helps to shape the electrophysiological properties of the cell and the neural network within which the cell functions. This proposal is aimed at filling this gap using the small, well-defined pyloric network in the crustacean stomatogastric ganglion. This network's 14 neurons are easily identified, and their unique physiological properties are well known. We are cloning the cDNAs of the four genes in the Shaker family (shaker, shab, shaw and shal), and determining their functions in each of the 14 identified cells in this pyloric network. To understand the roles of Shaker family currents in the generation of the pyloric network's motor pattern, we propose the following goals: 1) Clone the alternative splice variants of shaker, shab, shaw and shal form lobster. 2) Express these variants in Xenopus oocytes and lobster neurons, and compare their biophysical properties to endogenous currents in the stomatogastric neurons. 3) Map the expression of these variants in the individual identified neurons using a single cell PCR method that we have recently developed. 4) Artificially alter the expression of Shaker family genes by injecting sense or antisense RNA into identified STG neurons, and determine the effect or raising or lowering specific currents on the cellular and network properties and cellular responses to monamine modulators. The ultimate goal of this work is to answer why there are so many genes and splice variants for voltage-dependent K+ channels. Our studies will allow us to assign physiological roles to specific K+ channel genes in determining both the intrinsic firing properties of identified neurons and the motor pattern generated by the pyloric network.

描述（改编自申请人摘要）： 这四个基因编码大量的电压敏感性钾通道 在Shaker家族。 在果蝇中，其中三个基因 选择性剪接它们的mRNA，产生多种蛋白质， 不同的生物物理特性。 此外，单个基因的剪接变体 基因可以相互作用形成异源多聚体通道。 生理 这种钾通道多样性的作用还不清楚。 是 很难将特定基因与细胞中的离子电流联系起来， 并展示基因产物如何帮助塑造电生理 细胞和细胞所在的神经网络的性质 功能协调发展的 这项建议旨在利用小型、小型和小型的 在甲壳动物的口胃神经节中有明确的幽门网络。 这个网络的14个神经元很容易识别，它们的独特性 生理特性是众所周知的。 我们正在克隆 Shaker家族中的四个基因（shaker、shab、shaw和shal），以及 确定它们在这14个识别的细胞中的每一个中的功能， 幽门网络 为了理解Shaker家族电流在 为了生成幽门网络的运动模式，我们提出以下建议 目标： 1)克隆shaker，shab，shaw和shal形式的选择性剪接变体 龙虾. 2)在非洲爪蟾卵母细胞和龙虾神经元中表达这些变体， 并将它们的生物物理特性与大脑中的内源性电流进行比较， 口胃神经元 3)将这些变量的表达式映射到 使用单细胞PCR方法， 最近开发的。 4)牺牲性地改变Shaker家族的表达 通过将有义或反义RNA注射到鉴定的STG神经元中， 确定提高或降低特定电流对 细胞和网络特性以及细胞对单胺的反应 调制器。 这项工作的最终目标是回答为什么有这么多的基因， 电压依赖性K+通道的剪接变体。 我们的研究将使 我们分配生理作用，以特定的K+通道基因，在决定 识别出的神经元和运动神经元的固有放电特性 由幽门网络产生的模式。