NEURAL AND MUSCULAR CONTROL OF FINGER MOVEMENTS

描述：(改编自调查者摘要)移动 手指彼此相对独立，使得人类和非人类 灵长类动物操纵环境中的不同物体并执行 各种各样的动作和手势。运动皮质的损害，如 那些与中风有关的疾病会导致衰弱和持久的缺陷 在单独移动手指的能力上，即使在弯曲的能力 把手指放在一起就可以恢复了。因此，非常科学 人们的注意力集中在了解大脑的运动中枢是如何 赋予单独控制手指的能力。的功能 然而，外周运动设备在很大程度上被忽视了 解释与运动皮质组织有关的发现。在……里面 具体地说，主要负责移动手指的致动器是 远端长出多条肌腱的单腹肌 在所有的手指上。虽然目前的观点是这些多端的肌肉 由不同的功能隔间组成，这些隔间控制着不同 数字，研究人员最近表明，运动单位的力量在这些 肌肉不是集中在单个肌腱上，而是广泛分布的 横跨多条肌腱。这一观察引发了一些关于 对手指的神经和肌肉控制，在特定的 这项提议的目的。首先，是什么具体因素导致了扩散？ 控制肌肉中多个肌腱的运动单位力 手指？其次，在多大程度上可以移动手指 独立的。第三，神经系统采用什么策略？ 当尝试移动单个手指时，由于明显缺少 数字的独立执行器？这些问题将在人类身上得到解决 受试者使用各种电生理和生物力学技术， 包括神经内和肌肉内微刺激，相互关联 对同时运行的马达单元记录的尖峰序列进行分析， 来自多个肌肉的运动学分析和肌电记录 在执行个性化的手指动作时。这些研究的结果 研究将增加我们对脊椎和肌肉系统如何 在详细阐述手指动作时进行协调，并将提供 理解运动皮质如何指定自愿性的重要框架 手的动作。

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.