MECHANISMS OF RENSHAW CELL MEDIATED RECURRENT INHIBITION

已知抑制机制在运动控制中至关重要， 癫痫，麻醉，和许多其他正常和异常的方面， 神经功能 然而，目前，抑制机制的分析 是复杂的不确定性有关的解剖抑制 回路，突触后神经元上抑制性突触的位置， 以及不同类型的抑制性神经递质所使用的候选神经递质 中间神经元 在节段运动系统中，两种主要的抑制性 运动神经元的输入由可识别的中间神经元介导- Renshaw 细胞（介导复发抑制）和Ia抑制性中间神经元 （介导相互抑制）。 这一长期目标的实现 该提案旨在更好地了解Renshaw细胞的生理作用。 为了实现这一点，有必要将它们的特性与 至少一种其他抑制性输入的作用机制， 运动神经元 Ia抑制性中间神经元是很好的候选者 目的，因为它们自己的活动是由伦肖细胞的行动调制，因此， 直接连接两个系统控制电机输出。 的 实验将使用联合收割机结合细胞内记录和 鉴定的抑制性中间神经元及其突触后神经元的染色 目标，并随后分析，使用光学和电子显微镜， 植入后免疫金技术。 具体目标是继续 详细分析Renshaw细胞与运动神经元的连接， 特别强调地形和运动神经元类型如何影响 抑制性突触的发生率和分布。 类似的 将对Ia抑制系统进行一种类型的研究。 为 抑制系统，详细的超微结构和免疫细胞化学 将进行分析以确定它们的突触关系， 假定的神经递质

Inhibitory mechanisms are known to be crucial in motor control, epilepsy, anaesthesia, and many other normal and abnormal aspects of a neural function. At present, however, analyses of inhibitory mechanisms are complicated by uncertainties concerning the anatomy of inhibitory circuits, the location of inhibitory synapses on postsynaptic neurons, and the candidate neurotransmitters used by different kinds of inhibitory interneurons. In the segmental motor system two of the major inhibitory inputs to motoneurons are mediated by identifiable interneurons - Renshaw cells (mediating recurrent inhibition) and Ia inhibitory interneurons (mediating reciprocal inhibition). The continuing long term goal of this proposal is to better understand the physiological role of Renshaw cells. To achieve this, it is necessary to compare their properties with the mechanisms of action of at least one other inhibitory input to motoneurons. The Ia inhibitory interneurons are good candidates for this purpose as their own activity is modulated by Renshaw cell actions, thus directly linking the two systems in controlling motor output. The experiments will use techniques which combine intracellular recording and staining of identified inhibitory interneurons and their postsynaptic targets, and subsequent analysis, using light and electron microscopy and postembedding immunogold techniques. The specific aims are to continue the detailed analysis of Renshaw cell connections to motorneurons, with particular emphasis on how topography and motoneuron type might influence the incidence and distribution of the inhibitory synapses. A similar type of study will be performed on the Ia inhibitory system. For both inhibitory systems, detailed ultrastructural and immunocytochemical analyses will be performed to determine their synaptic relationships and putative neurotransmitters.