DYNAMICS OF MEMBRANE ORGANIZATION AT NODES OF RANVIER

RANVIER 节点膜组织动力学

• 批准号: 2262679
• 负责人: Mark H Ellisman
• 金额: $ 20.1万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-07-01 至 1999-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2262679
• 关键词: Rana; Schwann cells; calcium flux; chickens; developmental neurobiology; dyes; electrophysiology; immunofluorescence technique; immunologic assay /test; laboratory rat; membrane channels; membrane structure; microscopy; myelination; nerve /myelin protein; nervous system regeneration; neural conduction; node of Ranvier; phosphorylation; serotonin receptor; single cell analysis; tissue /cell culture; voltage gated channel

This project is focused on the node of Ranvier of myelinated nerve. The general goal is to extend our work on establishing a better understanding of how the node functions and to continue to identify the locations of macromolecules in the nodal complex that are important to conduction of the nerve impulse and development Specific aim I is to determine the sources, mechanisms and roles of[Ca2+]i transients and the sites of voltage transients in the nodal complex. The ultimate objectives of these studies are twofold: to gain a better understanding of (1) the roles of paranodal glia in the regulation of the nodal ionic milieu; and (2) the mechanisms underlying alterations in threshold and changes in conduction velocity that occur following impulse activity. Experiments are to be conducted using optical methods for recording of voltage and (Ca2+]i transients as well as time-lapse Nomarski imaging. In these experiments we will use optical methods to determine the structural and physiological effects of drugs known to alter specific ion conductances. Specific aim II involves studies of 5-HT receptors in Schwann cells. The objectives are to determine the type of 3-HT receptor responsible for Schwann cell [Ca2+]i transients in vitro and determine if these receptors are present in vivo. Specific aim IIl is to determine the sites of previously characterized and newly identified macromolecules in the node of Ranvier complex using immunolocalization techniques as well as to determine the sequence of appearance of macromolecules during development, regeneration and remyelination. The objectives of these studies are (1) to identify the precise locations of membrane proteins and other macromolecular constituents that we believe are important to nodal function and development; and (2) to study the developmental sequence for the appearance of the subset of these macromolecules that may be involved in defining the initial locations of nodes along premyelinated or remyelinating fibers. Our first experiments localizing macromolecules in the nodal complex win follow up on interesting preliminary results with newly characterized antibodies to K+ channels, ryanodine receptors, Na+/Ca2+ exchangers and H2O channels, as well as Na+/K+ ATPases, tyrosine kinases and proteins phosphorylated on tyrosine. Simultaneously we will conduct experiments aimed at gaining new insight into the initial stages of nodal development, remyelination and regeneration, using antibodies specific for the voltage dependent Na+ and K+ channels. In these experiments the aim is to determine the sequence of development of macromolecular components of the nodal complex. A special interest will be to determine if one of the constituents disclosed during the antibody localization studies appears prior to the arrival of myelinating cells thus participating in the early definition of the node of Ranvier. The results of these studies will provide a better understanding of the relationship between structure and function at the node of Ranvier and the underlying macromolecular basis for impaired conduction in demyelinating disease.

该项目的重点是髓神经的兰维尔节点。 这 一般目标是扩展我们建立更好理解的工作 节点的功能以及继续识别的位置 淋巴结络合物中的大分子对于传导很重要 我的神经冲动和发展特定目的是确定 [Ca2+] i瞬变的来源，机制和角色以及 节点复合物中的电压瞬变。这些的最终目标 研究是双重的：要更好地理解（1） 在淋巴结离子环境中的偏阳胶质； （2） 阈值改变和传导变化的机制 冲动活动后发生的速度。实验是 使用光学方法记录电压和（Ca2+] I 瞬态以及延时的Nomarski成像。在这些实验中，我们 将使用光学方法来确定结构和生理 已知会改变特定离子电导的药物的作用。具体目标II 涉及对雪旺细胞中5-HT受体的研究。目标是 确定负责Schwann细胞的3-HT受体的类型[Ca2+] I 体外瞬态并确定这些受体是否存在于体内。 具体目的是确定先前表征的地点，并且 使用Ranvier复合物节点中新鉴定的大分子 免疫定位技术以及确定的序列 在开发，再生和 再髓。这些研究的目标是（1）确定 膜蛋白和其他大分子的精确位置 我们认为对淋巴结功能很重要的成分和 发展; （2）研究 这些大分子的子集的外观可能涉及 定义沿前层的节点的初始位置或 透露纤维。我们的第一个实验将大分子定位在 Nodal Complex赢得的随访，以有趣的初步结果跟进 新特征的K+通道，ryanodine受体的抗体， Na+/Ca2+交换器和H2O通道，以及Na+/K+ ATPases，酪氨酸 激酶和蛋白质在酪氨酸上磷酸化。同时我们会的 进行旨在获得初始阶段的新见解的实验 使用抗体 针对依赖电压的Na+和K+通道。在这些 实验的目的是确定 淋巴结复合物的大分子成分。特别的兴趣将是 确定在抗体期间披露的成分之一 骨髓细胞到来之前出现了定位研究 因此参与了Ranvier节点的早期定义。这 这些研究的结果将更好地理解 Ranvier节点的结构与功能之间的关系 基础大分子基础，用于脱髓鞘的传导受损 疾病。