MECHANISMS OF RENSHAW CELL MEDIATED RECURRENT INHIBITION

众所周知，抑制机制在运动控制中至关重要， 癫痫、麻木和许多其他正常和不正常的方面 神经功能。然而，目前对抑制机制的分析 因有关抑制的解剖结构的不确定性而复杂化 回路，抑制性突触在突触后神经元上的位置， 以及不同种类的抑制性神经递质使用的候选神经递质 中间神经元。在节段性运动系统中有两个主要的抑制因素 运动神经元的输入由可识别的中间神经元调节-Renshaw 细胞(介导反复抑制)和Ia抑制中间神经元 (调节相互抑制)。这样做的持续长期目标是 建议是为了更好地了解伦肖细胞的生理作用。 要实现这一点，必须将它们的属性与 至少一种其他抑制输入的作用机制 运动神经元。Ia抑制的中间神经元是很好的候选者。 目的，因为它们自身的活动受伦肖细胞行为的调节，因此 在控制电机输出时，直接连接两个系统。这个 实验将使用结合细胞内记录和 已鉴定的抑制性中间神经元及其突触后的染色 靶以及随后的分析，使用光学和电子显微镜和 包埋后免疫金技术。具体目标是继续 Renshaw细胞与运动神经元的联系的详细分析， 特别强调地形和运动神经元类型可能会如何影响 抑制性突触的出现和分布。一种类似的 将对Ia抑制系统进行类型研究。对两个人都是 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和 可能是神经递质。

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.