SPINAL NEURON EXCITABILITY DURING VOLUNTARY MOVEMENT

拟议的实验是一项研究工作的组成部分， 长期目标是了解脊髓在 控制灵长类动物手臂的随意运动。这个目标包括搜索 治疗或干预，将克服运动缺陷相关的 脊髓损伤拟议的研究通过阐明这些目标， 支配前臂的脊髓中间神经元的功能组织 在正常的猴子身上的动作。全面了解正常 在研究运动损伤和恢复之前，脊髓功能是必不可少的 伤害可以被解释为有用的。项目的具体目标 是：1.怎么着是短的运动前脊髓本体中间神经元 位于灵长类手臂控制的颈膨大的喙侧， 手部动作？2.运动神经元和中间神经元的兴奋性是如何调节的 在正常的运动中受到神经调节剂血清素和去甲肾上腺素的影响 抑制对神经元的募集和空间调谐有何贡献？ 运动神经元和中间神经元颈部中间神经元的活动和 运动神经元将被记录在自愿达到，孤立的手腕 运动和收缩的屈肌和伸肌的手腕在 醒猴最初的双标记解剖实验将指导 通过识别运动前区的位置来寻找脊髓本体神经元 C3-C4节段中的中间神经元接受来自皮质脊髓的直接输入， 纤维脊髓神经元的抑制性和神经调质输入将被抑制。 用药理学试剂的局部离子电渗疗法操作， 阻断血清素、去甲肾上腺素、GABA或甘氨酸受体。输入和输出 中间神经元的连接将被识别为尖峰触发的平均值， EMG和外周传入神经的自然和电刺激， 下行通路这些研究将阐明 中间神经元和运动神经元的兴奋性在自主运动过程中受到控制， 为进一步研究运动机制奠定了基础 功能障碍和损伤恢复。

The proposed experiments are components of a research effort whose long-term objective is to understand the role played by the spinal cord in the control of voluntary movements of the primate arm. This goal includes a search for therapies or interventions that will overcome the motor deficits associated with spinal cord injury. The proposed study advances these goals by elucidating the functional organization of spinal interneurons controlling forearm movements in the normal, behaving monkey. A thorough understanding of normal spinal function is essential before studies of motor impairment and recovery following injury can be interpreted usefully. The specific aims of the project are: 1. What. is the role of short, premotor, propriospinal interneurons located rostral to the cervical enlargement in the control of primate arm and hand movements? 2. How are motoneuron and interneuron excitability regulated during normal movements by the neuromodulators serotonin and noradrenaline? What is the contribution of inhibition to the recruitment and spatial tuning of motoneurons and interneurons? The activity of cervical interneurons and motoneurons will be recorded during voluntary reaching, isolated wrist movements, and contraction of flexor- and extensor muscles of the wrist in the awake monkey. Initial double-labeling anatomical experiments will guide the search for propriospinal neurons by identifying the location of premotor interneurons in the C3-C4 segments that receive direct input from corticospinal fibers. Inhibitory and neuromodulator inputs to spinal neurons will be manipulated with local iontophoresis of pharmacological agents that activate or block serotonin,, noradrenaline, GABA or glycine receptors. Input and output connections of interneurons will be identified with spike-triggered averages of EMG and natural and electrical stimulation of peripheral afferents and descending pathways. These studies will elucidate the mechanisms by which the excitability of interneurons and motoneurons are controlled during voluntary movements and lay the foundation for future studies on the mechanisms of motor dysfunction and recovery from injury.