ANALYSIS OF THE RECURRENT RENSHAW CIRCUIT

这个建议是关于分析经常性的伦肖电路 目的是帮助我们理解经常性的作用， 抑制脊髓运动神经元的放电。 的 对这种双突触回路的分析将主要由 使用刺激单个运动轴突的技术， 为了记录小的突触后信号， 脊髓运动神经元中的电位由这种刺激产生。 使用 这些方法将解决一些具体问题。 的 单轴突复发性抑制性突触后电位的特征 （RIPSP）将被记录，以及这些关系 神经元间放电的特征。 RIPSP的分布 在一个homemorrhagic运动核将确定相对于 刺激轴突的运动单位类型和刺激轴突的运动单位类型。 运动神经元接受反复抑制。 RIPSP的分布 还将检查RIPSP“分割”的证据，即， 由神经支配特定肌肉区域的asons产生的RIPSPs， 最大的是支配同一肌肉区域的运动神经元。 如果发现这种划分，将分析其贡献， 地形特异性与物种特异性相比。 这些研究有望有助于我们了解 脊髓背角重复性抑制的组织结构及其功能意义 运动神经元，并且另外提供用于分析神经元的方法， 哺乳动物脊髓中涉及双突触和多突触的回路 连接. 本研究的最终健康相关目标是 有助于理解节段性运动功能的改变 控制机制，如发生在这样的国家，如痉挛，僵硬 和还押。

This proposal is concerned with analysis of the recurrent Renshaw circuit with the goal of contributing to our understanding of the role of recurrent inhibition in controlling the discharge of spinal motoneurons. The analysis of this disynaptic circuit will be accomplished primarily by the use of a technique for stimulating single motor axons in conjunction with spike-triggered averaging in order to record the small postsynaptic potentials in spinal motoneurons which result from such stimulation. Using these methods a number of specific issues will be addressed. The characteristics of single-axon recurrent inhibitory postsynaptic potentials (RIPSPs) will be documented as well as the relation of these characteristics to interneuronal discharge. The distribution of RIPSPs within a homonymous motor nucleus will be determined with respect to the motor-unit type of the stimulated axon and the motor-unit type of the motoneuron receiving the recurrent inhibition. The distribution of RIPSPs will also be examined for evidence of a "partitiioning" of RIPSPs, i.e., that RIPSPs produced by asons innervating a particular region of muscle are largest in those motoneurons which innervate that same region of muscle. Such a partitioning, if found, will be analyzed for contributions of topographic specificity in comparison to species specificity. These studies are expected to contribute to our understanding of the organization and functional significance of recurrent inhibition to spinal motoneurons and, in addition, to provide an approach for analyzing neuronal circuits in the mammalian spinal cord which involve di- and polysynaptic connections. The ultimate health-related goal of this study is to contribute to an understanding of altered function of segmental motor control mechanisms, such as occurs in such states as spasticity, rigidity and remor.