Spinal Neuron Excitability During Voluntary Movement

拟议的实验是一项研究工作的组成部分，其长期目标是了解 脊髓在控制灵长类动物手臂的随意运动中所起的作用。这一目标 包括寻找治疗或干预措施，以克服与脊髓损伤相关的运动缺陷。 脊髓损伤这项研究通过阐明脊髓的功能组织， 控制正常猴子前臂运动的中间神经元。的透彻理解 在研究运动损伤和损伤后的恢复之前， 解释有用。该项目的具体目标是：1。脊髓本体中间神经元的作用是什么 位于颈部膨大的喙部，控制灵长类动物的手臂和手部运动？2.好吗 运动神经元和中间神经元兴奋性在正常运动过程中通过抑制机制调节， 脊髓？3.脊髓运动神经元在自主运动中的正常活动是否依赖于 单胺的作用？在自主伸手过程中记录颈部神经元的活动， 腕部运动，以及清醒猴子腕部屈肌和伸肌的共同收缩。 对脊髓神经元的抑制性和神经调质输入将用以下局部离子电渗来操纵： 激活或阻断血清素、去甲肾上腺素、GABA或甘氨酸受体的药理学药剂。输入 和输出连接的中间神经元将确定与尖峰触发的平均肌电图和自然 以及外周传入神经和下行通路的电刺激。这些研究将阐明 在自主运动过程中控制中间神经元和运动神经元兴奋性的机制 为进一步研究运动功能障碍和康复的机制奠定基础 从受伤。

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 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 inhibitory mechanisms in the spinal cord? 3. Is the normal activity of spinal motoneurons during voluntary movement dependent on the action of monoamines? The activity of cervical neurons will be recorded during voluntary reaching, isolated wrist movements, and cocontraction of flexor and extensor muscles of the wrist in the awake monkey. 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.