ANALYSIS OF THE RECURRENT RENSHAW CIRCUIT

本提案的总体目标是检验以下假设： 脊髓复发性抑制调节运动神经元池的活动 在集中生成的活动中接收公共命令， 运动和抓挠。 这个实验室最近的工作表明 运动过程中常见的运动模式决定了 复发性抑制的分布。 上述假设具有 将这些发现与其他重要特征相结合 的组织结构。 有三个具体的 目标。 第一个具体目标是比较经常性组织 抑制和Ia相互抑制之间的运动神经元池， 控制脚踝。 Aim-1研究将提供必要的数据， 对复发性抑制和Ia的组织进行了严格的比较 对运动活动模式和组织的相互抑制 由中枢产生的运动指令 这些信息将用于 测试第二特定目标的假设。 第二特定 目的是检验这一假设，即运动神经元池是 通过反复抑制相互连接，接收共同的运动指令 在中枢运动活动中。 在这些研究中， 运动模式之间的互相关和相干函数 选择后肢运动神经元池将在虚构期间进行检查。 移动和虚构的抓挠 运动神经元池， 运动指令，如交叉相关性和相干性所示， 功能，将比较模式的复发性抑制和Ia 运动神经元池之间的相互抑制。 第三个具体目标 是为了验证复发性抑制调节运动输出的假设 在中枢产生的运动活动期间，通过指挥运动指令 最活跃的车辆调配场 Ia反射的振幅和比率 在不同的汽车池的反应将被检查期间虚构的 Aim-3研究中的运动和抓挠。 这些数值将被 根据已知的复发性抑制模式进行评价， 单突触Ia投射。 它们也将在以下方面进行比较： 胆碱能拮抗剂在阻断复发性抑制中的应用。 这项建议的健康相关意义在于，这些研究 将提供有关通过反复抑制 运动神经元池的相对活动程度。 这个脊髓回路 受棘上中枢的控制， 在疾病和脊髓损伤，伴随着恶化， 运动活动的调节。

The overall goal of this proposal is to examine the hypothesis that spinal recurrent inhibition regulates activity across motoneuron pools that receive common commands during centrally generated activities like locomotion and scratching. Recent work from this laboratory suggests that common patterns of motor activity during locomotion determine the distribution of recurrent inhibition. The hypothesis stated above has been formulated to integrate these findings with other important features of the organization of recurrent inhibition. There are three specific aims. The first specific aim is to compare the organization of recurrent inhibition and Ia reciprocal inhibition between motoneuron pools that control the ankle. Aim-1 studies will provide data necessary to provide a rigorous comparison of the organization of recurrent inhibition and Ia reciprocal inhibition to patterns of motor activity and the organization of centrally generated motor commands. This information will be used in testing the hypothesis for the second specific aim. The second specific aim is to test the hypothesis that motoneuron pools that are interconnected by recurrent inhibition receive common motor commands during centrally generated motor activities. In these studies, crosscorrelation and coherence functions between motor patterns of selected hindlimb motoneuron pools will be examined during fictive locomotion and fictive scratching. Motoneuron pools that receive common motor commands, as indicated by the crosscorrelation and coherence functions, will be compared to patterns of recurrent inhibition and Ia reciprocal inhibition between motoneuron pools. The third specific aim is to test the hypothesis that recurrent inhibition tunes motor output during centrally generated motor activities by directing motor commands to the most active motor pools. The amplitudes and ratios of Ia reflex responses in different motor pools will be examined during fictive locomotion and scratching in the Aim-3 studies. These values will be evaluated in relation to known patterns of recurrent inhibition and monosynaptic Ia projections. They will also be compared following the application of cholinergic antagonists to block recurrent inhibition. The health related significance of this proposal is that these studies will provide information about the regulation by recurrent inhibition of the relative degree of activity in motoneuron pools. This spinal circuit is subject to control from supraspinal centers, which may be interrupted in disease and spinal injury, with attendant deterioration in the regulation of motor activity.