ANALYSIS OF THE RECURRENT RENSHAW CIRCUIT

本建议涉及组织和职能 脊髓复发抑制的意义。 在这方面的重点是 建议是由假设，脊髓复发性抑制 行为，使运动神经元放电， 共同的突触驱动 这一假设将通过比较 运动神经元同步化的发生率和幅度 运动活动之前和之后的阻断复发 通过给予胆碱能拮抗剂进行抑制。 自发 活动将通过刺激中脑 运动区，运动神经元同步将被检测到 并使用校正的神经图的平均值进行量化。 在 的增订条文 不同肌肉之间的同步模式 将比较各组复发性抑制的分布 运动神经核 将开展其他项目， 研究重复性抑制在配对之间的分布 运动神经元的数量是它们之间距离的函数， 以获得对地震的位置、震级和时间进程的估计， 反复出现的抑制性突触后电位的传导。 将执行这些项目，以确定 从单个运动神经元到其他运动神经元的反复抑制 运动神经元池中的运动神经元，并确定潜在的 复发抑制的强度。 这些研究将在 使用细胞内记录技术。 确定 不同水平运动神经元的功能后果 同步，将检查同步的效果 在等长和负载移动过程中力的发展 由少数运动神经活动引起的收缩 单位 最后，研究了复发性抑制对 放电，运动神经元群体的特征将被 在模拟中检查。 这些模拟的目的是 确定运动神经元池性能的灵敏度 复发性抑制的强度和分布的变化 以及中枢兴奋性驱动的不同来源。 的项目 这一建议将有助于了解中央 神经系统和神经肌肉疾病， 相关的运动障碍。

This proposal is concerned with the organization and functional significance of spinal recurrent inhibition. The emphasis in this proposal is on the by hypothesis that spinal recurrent inhibition acts to desynchronize motoneuron discharge which occurs due to common synaptic drive. This hypothesis will be rested by comparing the incidence and magnitude of motoneuron synchronization during locomotor activity before and after blockage of recurrent inhibition by administration of cholinergic antagonists. Locomotor activity will be evoked by stimulation of the mesencephalic locomotor region, and motoneuron synchronization will be detected and quantified using averages of rectified neurograms. In addition. Patterns of synchronization between different muscle groups will be compared to the distribution of recurrent inhibition to their motor nuclei. Other projects will be performed to investigate the distribution of recurrent inhibition between pairs of motoneurons as a function of the distance separating them and to obtain estimates of the location, magnitude and time course of the conductance of recurrent inhibitory postsynaptic potentials. These projects will be performed to determine the extent of recurrent inhibition from individual motoneurons to other motoneurons in a motoneuron pool, and to determine the potential strength of recurrent inhibition. These studies will be performed using intracellular recording techniques. To determine the functional consequences of varying levels of motoneuron synchronization, the effects of synchronization will be examined on the development of force during isometric and load-moving contractions produced by activity of a small population of motor units. Finally, the effect of recurrent inhibition on the discharge, characteristics of a population of motoneurons will be examined in simulations. The intent of these simulations is to determine the sensitivity of the performance of a motoneuron pool to changes in the strength and distribution of recurrent inhibition and to different sources of central excitatory drive. The projects in this proposal will contribute to understanding of central nervous system and neuromuscular diseases producing tremor and associated motor disorders.