RECURRENT RENSHAW CIRCUIT

描述：（申请人摘要）本提案的总体目标是 确定集中产生的组织之间的关系 运动命令和已知的复发性抑制模式，以及 研究两套机制，可能会决定这种影响， 抑制运动和姿势活动期间的运动神经元池。 该实验室最近的工作表明：1）Renshaw细胞， 抑制协同运动核可以形成连接的中间神经元网络 通过相互抑制; 2）Renshaw细胞产生的复发性抑制 可能通过突触相互作用影响运动神经元的活动， 运动神经元的树突树;和3）Renshaw的分布 抑制与运动命令的分布相关， 支配近端肢体肌肉的运动核团。 研究已经 本提案旨在解决与这些问题有关的三个目标 意见。 第一个具体目标是检验伦肖的假设， 由运动神经元的两组激活的细胞是相互抑制的。 如果这一假设得到证实， 将确定相互抑制。 第二个具体目标是 确定突触和内在电流的位置， 运动神经元的树突状乔木。 在这些研究中， Renshaw抑制和几种突触和内在电流， 将检查运动神经元。 第三个具体目标是比较 不同功能组的突触电位模式 运动神经元在运动活动中。 这些研究将解决几个 关于运动的中央组织的问题，它与 反复抑制的组织和相关方法的能力 来评估脊髓运动指令的组织。 伦肖抑制 与大多数肢体肌肉的运动神经元池有关， 受到脊髓损伤和上运动神经元疾病的影响 拟议 研究将提供关于控制 运动神经元池的Renshaw抑制和中断的影响， 脊柱系统控制的疾病或损伤。

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.