MECHANICAL, THERMAL, AND OPTICAL SIGNS OF EXCITATION IN THE NERVOUS SYSTEM

神经系统兴奋的机械、热和光学迹象

• 批准号: 3781396
• 负责人: I Tasaki
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF MENTAL HEALTH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3781396
• 关键词: Osteichthyes; alternatives to animals in research; calcium; divalent cations; electrophysiology; electrostimulus; fish electric organ; gel; heat; ion transport; nervous system; neurophysiology; physical chemical interaction; sodium

We have concentrated, during the major portion of this fiscal year, on elucidation of the physico-chemical basis of the rapid structural changes in the nerve fibers and cells associated with the excitation process. The fact that nerve fibers and cells undergo rapid structural changes when they are excited was discovered and established in this laboratory. Hence, we deem it highly important to direct our efforts toward elucidating how these rapid structural changes are evoked by electric stimulation of excitable tissues. With this aim, we have expanded our analysis of the phenomenon of discontinuous volume phase transition associated with Ca-Na ion- exchange in inanimate anionic gels. We prepared gel samples by free radical copolyinerization of acrylic acid. By determining the degree of gel swelling as a function of mole fraction of the divalent cations in the solution, a phase-diagram was constructed. By recording rapid contractions of thin gel membranes, the factors which determine the rate of transition from a swollen to a shrunken state was clarified. Finally, based on the results of these studies, we have proposed a new, physico-chemical explanation of the excitation process in nerve fibers and cells. In May of this fiscal year, we started to investigate mechanical and thermal signs of the excitation process in the electric organ of the electric eel. It was not difficult for us to demonstrate rapid swelling of the functional units, electroplates, associated with the production of an action potential. Although our study is still in an early stage, we are expecting to gain significant experimental support of our basic idea concerning the mechanism of nerve excitation.

在本财政年度的大部分时间里， 阐明快速结构变化的物理化学基础 在神经纤维和细胞中与兴奋过程有关。 神经纤维和细胞经历快速的结构变化 是在这个实验室里发现并建立的。 因此，我们认为非常重要的是， 阐明了这些快速的结构变化是如何被电诱发的 刺激可兴奋组织。 为此，我们扩大了 不连续体积相变现象的分析 与无生命阴离子凝胶中的Ca-Na离子交换有关。 我们 通过丙烯酸的自由基共聚反应制备凝胶样品。 通过确定凝胶溶胀度作为摩尔分数的函数， 的溶液中的二价阳离子，相图构建。 通过记录薄凝胶膜的快速收缩， 确定从膨胀状态到收缩状态的转变速率是 明确了最后，根据这些研究的结果，我们有 提出了一个新的，物理化学解释的激发过程 在神经纤维和细胞中。 本财年5月，我们开始调查机械和 热信号的兴奋过程中的电器官的 电鳗 我们不难证明快速肿胀 与生产相关的功能单元，电镀， 一个动作电位。 虽然我们的研究还处于早期阶段， 我们期待着获得重要的实验支持， 关于神经兴奋机制的观点。