FATIGUE OF SEGMENTAL MOTOR MECHANISMS

分段电机机构的疲劳

• 批准号: 2265455
• 负责人: DOUGLAS A STUART
• 金额: $ 21.17万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-09-01 至 1996-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2265455
• 关键词: Chelonia; alternatives to animals in research; cats; degenerative motor system disease; fatigue; neuromuscular function; neuromuscular system

Muscle fatigue encompasses a class of acute effects which impair motor performance. The mechanisms that produce fatigue may involve all elements of the motor system, from a formulation of the descending drive provided by suprasegmental centers to a reduction in the activity of muscle contractile proteins. Recently our laboratory has proposed four themes that provide a basis for the systematic evaluation of the neural and neuromuscular mechanisms that can contribute to fatigue: (1) task dependency -- to identify the conditions that activate the various fatigue mechanisms; (2) force-fatigability relationship -- to explore the interactions between the mechanisms that result in a hyperbolic relationship between force and endurance time; (3) muscle wisdom -- to examine the association between a concurrent decline in muscle relaxation rate and motor neuron discharge during fatigue that results in an optimization of force; and (4) sense of effort -- to determine the role of perceived effort in the impairment of performance. This project addresses the first three of these themes, and several of our Aim 1 techniques permit a cellular neurophysiological approach to the sense of effort. Thus, this project is an essential component of a broadly based four-theme approach to understanding the neurobiology of muscle fatigue. Segmental motor mechanisms is a term used to describe the integrated (systems) operation of brainstem/spinal motor circuitry, motor units, muscle receptors and the segmental actions of muscle-, joint- and cutaneous afferents. This project links study of the fatigue of segmental motor mechanisms to the quadripartite approach described above. Aim 1 addresses task dependency and muscle wisdom; it involves quantifying the adaptation of motor neuron discharge during sustained and intermittent stimulation when the spinal cord is passive (i.e., not generating a rhythmic motor output) or active (i.e., when generating a rhythmic motor output). Aim 2 addresses task dependency and the force-fatigability relationship and examines how the CNS might exploit the catch-like property of skeletal muscle and the stimulus frequency-force relationship to reduce and delay fatigue. Both sets of experiments will be undertaken on decapitated turtles, an animal species which is particularly well suited for the study of spinal cord-muscle relationships. It is anticipated that these studies will contribute information on fundamental issues in motor control that have not yet been resolved. Furthermore, the work has profound implications for orthopedics, sports medicine, the fatigability that is evident in various effort syndromes that accompany higher brain malfunctions, motor recovery after brain damage, many neuromuscular diseases, peripheral neuromuscular damage, functional electrical stimulation, and the emerging field of motor prosthetics.

肌肉疲劳包括一类急性效应， 性能 产生疲劳的机制可能涉及所有的元素 的电机系统，从公式的下降驱动器提供的 超节段中心的活动减少肌肉收缩 proteins. 最近，我们的实验室提出了四个主题， 神经和神经肌肉系统评价的基础 可能导致疲劳的机制：（1）任务依赖性-- 确定激活各种疲劳机制的条件;（2） 力-疲劳关系--探讨 导致力和力之间的双曲线关系的机制 耐力时间;（3）肌肉智慧-检查之间的关联 肌肉松弛率和运动神经元放电同时下降 在疲劳期间，导致力的优化;以及（4） 努力--确定感知的努力在损害中的作用， 性能 本项目涉及前三个主题， 我们的几个目标1技术允许细胞神经生理学 接近努力的感觉。 因此，该项目是一个重要的 基础广泛的四个主题办法的组成部分， 肌肉疲劳的神经生物学 节段性运动机制是一个术语，用于描述 （系统）脑干/脊髓运动电路的操作，运动单位， 肌肉受体和肌肉、关节和皮肤的节段性作用 传入神经 本项目结合节段性运动疲劳的研究 上述四方办法的机制。 目标1： 任务依赖性和肌肉智慧;它涉及量化的适应 运动神经元放电在持续和间歇刺激 当脊髓是被动的（即，不产生节律运动 输出）或活动（即，当产生有节奏的运动输出时）。 目的2 解决了任务依赖性和力-疲劳关系， 研究了中枢神经系统如何利用骨骼肌的捕获样特性， 肌肉和刺激频率-力的关系，以减少和延迟 疲劳 这两组实验都将在斩首的情况下进行 海龟，一种特别适合研究的动物物种， 脊髓和肌肉的关系 预计这些研究将提供以下信息： 运动控制中尚未解决的基本问题。 此外，这项工作对骨科、体育、 医学，疲劳，这是明显的各种努力综合征， 伴随着更高的脑功能障碍，脑损伤后的运动恢复， 许多神经肌肉疾病，周围神经肌肉损伤，功能性 电刺激和新兴的运动假肢领域。