RECURRENT RENSHAW CIRCUIT

描述：(申请人摘要)这项提案的总体目标是 确定集中生成的组织之间的关系 运动指令和已知的反复抑制模式，以及 研究两套可能决定这一结果的机制 运动和姿势活动时对运动神经元池的抑制。 本实验室最近的研究表明：1)伦肖细胞 抑制协同运动核团可能形成一个相互连接的中间神经元网络 通过相互抑制；2)伦肖细胞产生的反复抑制 可能通过突触相互作用影响运动神经元的活动。 运动神经元的树突；3)Renshaw的分布 抑制与运动指令的分配有关 支配四肢近端肌肉的运动核团。研究表明， 本提案计划解决与以下三个目标相关的问题 观察。第一个具体目标是检验伦肖的假设 被运动神经元协同群激活的细胞是相互抑制的。 如果这一假设得到证实，这一现象的强度和分布 相互抑制将被确定。第二个具体目标是 确定突触电流和内源性电流在 运动神经元的树状乔木。在这些研究中， Renshaw抑制与脑内几种突触和内源性电流 将对运动神经元进行检查。第三个具体目标是比较 不同功能基团的突触电位模式 运动活动中的运动神经元。这些研究将涉及几个 关于中央运动组织的问题，它与 反复抑制的组织和相关方法的能力 以评估脊椎运动指令的组织。伦肖抑制 与肢体肌肉的大多数运动神经元池有关，及其调节 受到脊椎损伤和上运动神经元疾病的影响。建议数 研究将提供关于#年活动控制的信息。 Renshaw抑制对运动神经元池的抑制及其对其干扰的影响 脊髓损伤控制这一脊椎系统的疾病或损伤

DESCRIPTION: (Applicant's abstract) The overall goal of this proposal is to determine the relation between the organization of centrally generated locomotor commands and known patterns of recurrent inhibition, and to investigate two sets of mechanisms that may determine the effect of this inhibition on motoneuron pools during locomotor and postural activity. Recent work from this laboratory suggests that: 1) the Renshaw cells which inhibit synergistic motor nuclei may form a network of interneurons linked by mutual inhibition; 2) the recurrent inhibition produced by Renshaw cells may affect the activity of motoneurons through synaptic interactions in the dendritic trees of motoneurons; and 3) the distribution of Renshaw inhibition is correlated with the distribution of locomotor commands to motor nuclei that innervate proximal limb muscles. Studies have been planned for this proposal to address three aims related to these observations. The first specific aim is to test the hypothesis that Renshaw cells activated by synergist groups of motoneurons are mutually inhibitory. If this hypothesis is confirmed, the strength and distribution of this mutual inhibition will be determined. The second specific aim is to determine the location of synaptic and intrinsic currents within the dendritic arbors of motoneurons. In these studies, interactions between Renshaw inhibition and several synaptic and intrinsic currents in motoneurons will be examined. The third specific aim is to compare the patterns of synaptic potentials to different functional groups of motoneurons during locomotor activity. These studies will address several issues concerning the central organization of locomotion, its relation to the organization of recurrent inhibition, and ability of correlation methods to assess the organization of spinal locomotor commands. Renshaw inhibition is associated with most motoneuron pools of limb muscles, and its regulation is compromised by spinal injury and upper motoneuron disease. The proposed studies will provide information on the control of the activity in motoneuron pools by Renshaw inhibition and the implications of disruption by disease or injury of control of this spinal system.