Coordination deficits after peripheral nerve injury

这个项目的长期目标是了解运动和目标达成过程中运动协调的短潜伏期本体感受反馈损失的后果。神经切断后肌肉的自我神经支配可能导致有效本体感受反馈的永久性丧失。周围神经损伤也可能导致灵活性或运动协调的长期中断，即使在神经再生之后。该项目的中心假设是，来自肌肉prioprioceptor的感觉反馈提供了协调和自愿运动行为的持续调节，并且这种反馈的丧失导致运动协调的永久性缺陷。将通过使用自我神经再支配方法从猫的选定肌肉中去除有效反馈并在恢复运动功率后评价这些动物的运动性能来检验该假设。首先将确定来自肌梭受体和高尔基体腱器官的本体感受反馈的肌间分布。这些通路的作用将通过拉伸个体肌肉或扰动去大脑动物的前肢，然后测量产生的力或肌电图反应来测量。这些数据将用于确定最重要的感官反馈来源。在其他方面完好的动物中，通过引起选定肌肉的自我神经再支配（这些肌肉为前肢中的其他肌肉提供关键反馈），评价由这种反馈丧失导致的运动缺陷。动物在斜坡表面上运动或目标伸展运动期间将被拍摄。基于类似的研究，使用后肢，去除有效的反馈，预计会产生损失的关节间协调下斜坡和难以终止运动的前肢。将通过行为任务的长期经验评价这些动物补偿这些缺陷的能力。该项目将评估肌肉的感觉反馈对随意运动协调的作用，以及周围神经损伤后协调丧失的机制。

The long-term goal of this project is to understand the consequences of the loss of short-latency proprioceptive feedback for motor coordination during locomotion and targeted reaching. Self-reinnervation of muscle following transection of the nerve can lead to a permanent loss of effective proprioceptive feedback. Peripheral nerve injury can also lead to a long-term disruption of dexterity or motor coordination, even after regrowth of the nerve. The central hypothesis for this project is that sensory feedback from muscle prioprioceptors provides ongoing regulation of coordination and during voluntary motor behavior, and that the loss of this feedback leads to permanent deficits in motor coordination. This hypothesis will be tested by using the method of self- reinnervation to remove effective feedback from selected muscles in the cat and evaluating the motor performance of these animals following the restoration of motor power. The intermuscular distribution of proprioceptive feedback from muscle spindle receptors and Golgi tendon organs will first be determined. Actions of these pathways will be measured by stretching individual muscles or perturbing the forelimb in decerebrate animals and then measuring the resulting force or electromyographic responses. These data will be used to determine the most important sources of sensory feedback. Motor deficits resulting from loss of this feedback will be evaluated in otherwise intact animals by causing the self-reinnervation of selected muscles that supply critical feedback to other muscles in the forelimb. Animals will be filmed during locomotion on ramp surfaces or during targeted reaching movements. Based on similar studies using the hindlimb, the removal of effective feedback is expected to produce a loss of interjoint coordination down a ramp and difficulty in terminating movements of the forelimb. The ability of these animals to compensate for these deficits will be evaluated by long-term experience on the behavioral task. This project will constitute an evaluation of the role of sensory feedback from muscles on the coordination of voluntary movements and of the mechanisms underlying the loss of coordination following peripheral nerve injury.