MOTOR UNIT ORGANIZATION

本研究旨在研究具有不同轴突传导的运动单位。 与神经支配的肌肉纤维数量有关的速度，它们的 横截面面积和比张力(公斤/平方厘米)。数据应该是 指出这些变量中的哪个变量负责精确和 轴突大小和力之间的重要关系在 耐疲劳的马达单元。在这样的单元中，记录10个最大强直性张力 轴突传导速度与轴突传导速度呈近似线性关系。单电机 猫腰浅肌轴突在腹侧分离 根、传导速度测定和一个单位的肌纤维标记 在活动过程中与C142-脱氧葡萄糖。使用浅表的腰椎 有2个磁头，可以在单个单元之间进行成对的比较 避免因动物间差异而引入的数据分散。 将测量标记纤维的数量和直径；比张力 将由最大强直性张力除以横截面得出 单位纤维的面积。停用后也会进行类似的测量 (肌腱切断术)，以确定哪些变量被改变。这与以下内容相关 不使用会导致肌肉发生深刻变化的临床状况。 还将对神经挤压后重新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 分配。这对神经的临床问题有明显的影响。 损伤和神经再支配。

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.