NEURAL AND MUSCULAR CONTROL OF FINGER MOVEMENTS

描述：（改编自研究者的摘要）移动物体的能力 彼此相对独立的手指使人类和非人类能够 灵长类动物能够操纵环境中的不同物体并执行 各种各样的动作和手势。运动皮层损伤，例如 与中风相关的那些会导致衰弱和持续的缺陷 即使有弯曲能力，也能单独移动手指 并伸展手指并拢即可恢复。据此，许多科学 人们的注意力已经转向了解大脑的运动中枢如何 赋予单独控制手指的能力。的功能 然而，外围运动装置在很大程度上被忽视了 解释与运动皮层组织相关的发现。在 特别是，主要负责移动手指的执行器是 单腹肌肉，向远端产生多个插入的肌腱 到所有的手指上。虽然目前的观点是这些多端肌肉 由不同的功能区组成，控制不同的运动 数字，研究人员最近表明，这些运动单位的力量 肌肉并不集中在单个肌腱上，而是广泛分布 跨越许多肌腱。这一观察引发了一系列关于 具体解决了手指的神经和肌肉控制问题 本提案的目的。首先，具体有哪些因素会导致扩散？ 控制肌肉中多个肌腱的运动单位力 手指？其次，手指实际上可以移动到什么程度？ 独立。第三，神经系统采用什么策略 当尝试移动单个手指时，由于明显没有 数字的独立执行器？这些问题将在人性化的过程中得到解答 使用各种电生理学和生物力学技术的受试者， 包括神经内和肌肉内微刺激、互相关 分析同时活动的运动单位记录的尖峰序列， 来自多个肌肉的运动学分析和肌电图记录 在执行个性化手指动作的过程中。这些结果 研究将加深我们对脊柱和肌肉系统如何运作的理解 在手指运动的精细化过程中得到协调，并将提供 理解运动皮层如何指定自愿的重要框架 手的运动。

DESCRIPTION: (adapted from Investigator's abstract) The ability to move the fingers relatively independently of one another enables human and non-human primates to manipulate diverse objects in the environment and to execute an immense variety of movements and gestures. Lesions of the motor cortex, such as those associated with stroke, give rise to debilitating and persistent deficits in the ability to move fingers individually even though the capacity to flex and extend the fingers together recovers. Accordingly, much scientific attention has been directed toward understanding how motor centers of the brain impart the ability to separately control the fingers. The function of the peripheral motor apparatus, however, has been largely ignored in the interpretation of findings related to the organization of the motor cortex. In particular, the actuators primarily responsible for moving the fingers are single-bellied muscles that give rise distally to multiple tendons that insert onto all the fingers. While the current view is that these multiendoned muscles consist of distinct functional compartments that govern the motion of different digits, the investigators have recently shown that motor unit force in these muscles is not concentrated on a single tendon but is broadly distributed across many tendons. This observation promotes a number of questions about the neural and muscular control of the fingers that are addressed in the specific aims of this proposal. First, what specific factors contribute to the dispersal of motor unit force across multiple tendons in muscles that control the fingers? Second, to what extent is it actually possible to move the fingers independently. And third, what strategies are employed by the nervous system when attempting to move a single finger given the apparent absence of independent actuators of the digits? These questions will be addressed in human subjects using a variety of electrophysiological and biomechanical techniques, including intraneural and intramuscular microstimulation, cross-correlation analysis of spike trains recorded from concurrently active motor units, kinematic analysis, and electromyographic recordings from multiple muscles during the execution of individuated finger movements. The results from these studies will add to our comprehension of how the spinal and muscular systems are coordinated in the elaboration of finger movements and will provide an important framework for understanding how the motor cortex specifies voluntary motion of the hand.