Coordination deficits after peripheral nerve injury

该项目的长期目标是了解在运动和目标到达过程中失去短潜伏期本体感觉反馈对运动协调的影响。神经横断后的肌肉自我神经再生可导致有效本体感觉反馈的永久丧失。周围神经损伤也可能导致长期的灵活性或运动协调的中断，即使在神经再生后也是如此。该项目的中心假设是，来自肌肉priopripri感受器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。这一假设将通过使用自我神经再生的方法来验证，该方法从猫的选定肌肉中去除有效的反馈，并评估这些动物在运动动力恢复后的运动表现。首先确定来自肌梭形受体和高尔基肌腱器官的本体感觉反馈的肌间分布。这些通路的作用将通过拉伸单个肌肉或干扰失智动物的前肢来测量，然后测量产生的力或肌电反应。这些数据将用于确定最重要的感官反馈来源。这种反馈丧失导致的运动缺陷将在其他完好的动物中进行评估，通过对前肢其他肌肉提供关键反馈的选定肌肉进行自我神经再支配来评估。动物将在坡道表面或目标到达运动期间进行拍摄。基于对后肢的类似研究，去除有效反馈预计会导致下坡时关节间协调性的丧失，以及前肢终止运动的困难。这些动物补偿这些缺陷的能力将通过长期的行为任务经验来评估。该项目将评估来自肌肉的感觉反馈对自主运动协调的作用，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.