CENTRAL CONTROL OF MOTONEURONS IN A VERTEBRATE

运动系统研究的主要目标之一是 是为了了解中枢神经系统 控制运动神经元的激活， 行为。 运动行为背后的网络最容易 在鱼类和两栖动物中进行了研究，因为数量较少， 它们的神经元比哺乳动物的大。 的 所提出的实验旨在检查脊髓回路 在两个阶段中控制不同的轴向运动神经元群体， 金鱼的运动行为非常不同-- Mauthner细胞和正常游泳。 将使用细胞内记录和HRP染色技术 收件人： 1)检查识别出的中间神经元的输出连接， M细胞的脊髓网络。 这些数据将提供重要的 关于所识别的中间神经元在神经元中的作用的信息。 一个明确的脊椎动物运动行为网络。 2)确定哪些神经元是多突触活动的M- cell. 这些数据将允许详细比较 通过M细胞网络激活运动神经元和中间神经元 游泳网。 3)确定哪些脊髓中间神经元和运动神经元是活跃的 在金鱼的虚构游泳过程中，作为与 M细胞网络和脊髓网络都是游泳的基础 其他脊椎动物 4)直接决定突触输入个体中间神经元 从两个网络接收，以评估脊髓损伤的程度， 中间神经元由两者共享。 5)研究游泳和M细胞网络之间的相互作用 通过在虚构的游泳过程中引发M细胞启动的逃逸 插曲。 这些实验将提供有关中央的基本信息 控制轴向运动神经元激活的机制 金鱼 因为之前的研究表明， 脊椎动物脊柱运动系统的组织， 结果可能会提供一般的见解机制， 包括人类在内的脊椎动物运动神经元的控制。

One of the primary goals of studies of the motor systems of vertebrates is to understand how the central nervous system controls the activation of motoneurons to generate different motor behaviors. The networks underlying motor behaviors are most easily studied in fish and amphibians because of the smaller number and larger size of their neurons relative to those in mammals. The proposed experiments are designed to examine the spinal circuitry that controls different populations of axial motoneurons during two very different motor behaviors in goldfish - escapes initiated by the Mauthner cell and normal swimming. Intracellular recording and HRP staining techniques will be used to: 1) examine the output connections of identified interneurons in the spinal network of the M-cell. These data will provide essential information about the role of identified interneurons in the network of a well defined vertebrate motor behavior. 2) determine what neurons are polysynaptically activity by the M- cell. These data will permit a detailed comparison between the activation of motoneurons and interneurons by the M-cell network and the swimming network. 3) determine what spinal interneurons and motoneurons are active during fictive swimming in goldfish, as a basis for comparison with both the M-cell network and the spinal network for swimming on other vertebrates. 4) determine directly what synaptic inputs individual interneurons receive from both networks to evaluate the extent to which spinal interneurons are shared by the two. 5) examine interactions between the swimming and M-cell networks by eliciting a M-cell initiated escape during fictive swimming episode. These experiments will provide basic information about the central mechanisms for controlling the activation of axial motoneurons in goldfish. Because previous work indicates broad similarities in the organization of spinal motor systems in vertebrates, the results are likely to provide general insights into mechanisms for control of motoneurons in vertebrates, including humans.