MOTOR UNIT ORGANIZATION

电机组结构

• 批准号: 3414000
• 负责人: CARLTON C HUNT
• 金额: $ 16.73万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-09-01 至 1994-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3414000
• 关键词: axon; cats; denervation; fatigue; innervation; motor neurons; muscle tension; myofibrils; neural conduction; radiotracer; synapses; tetany

This research aims to study motor units having different axonal conduction velocities with respect to the number of muscle fibres innervated, their cross sectional areas and specific tensions (kg/cm2). The data should indicate which of these variables is responsible for the precise and important relation between axonal size and force developed in fatigue-resistant motor units. In such units log 10 maximal tetanic tension shows a nearly linear relation to axonal conduction velocity. Single motor axons to superficial lumbrical muscle of cat will be isolated in ventral root, conduction velocity determined and muscle fibres of a unit labeled with C14 2-deoxyglucose during activity. Using superficial lumbrical which has 2 heads, comparisons between pairs of units can be made in single animals, avoiding scatter in data introduced by interanimal variation. Numbers and diameters of labeled fibres will be measured; specific tension will be derived from maximal tetanic tension divided by cross sectional area of unit's fibres. Similar measurements will be made after disuse (tenotomy) to determine which variables are altered. This is relevant to clinical conditions in which disuse leads to profound changes in muscle. Studies will also be made in muscles reinnervated after nerve crush to determine fibre numbers, areas, specific tensions and spatial distributions. This has clear implications for clinical problems of nerve injury and reinnervation.

本研究旨在研究具有不同轴突传导的运动单位 速度与受神经支配的肌纤维数量有关， 横截面积和比张力 (kg/cm2)。数据应该 表明这些变量中的哪一个负责精确和 轴突大小和力之间的重要关系 抗疲劳运动单位。在这样的单位中记录 10 最大强直张力 显示与轴突传导速度几乎呈线性关系。单电机 猫的浅表蚓肌的轴突将在腹侧被分离 确定根部、传导速度并标记单位的肌纤维 活动期间与 C14 2-脱氧葡萄糖。使用浅表蚓状 有 2 个头，成对单元之间的比较可以在单个单元中进行 动物，避免动物间变异引入的数据分散。 将测量标记纤维的数量和直径；比张力 将由最大强直张力除以横截面得出 单位纤维的面积。废弃后将进行类似的测量 （腱切断术）以确定哪些变量被改变。这与 不使用会导致肌肉发生深刻变化的临床情况。 还将对神经受压后重新受神经支配的肌肉进行研究 确定纤维数量、面积、特定张力和空间 分布。这对神经的临床问题具有明显的意义 损伤和神经再生。