CENTRAL CONTROL OF MOTONEURONS IN A VERTEBRATE

运动系统研究的主要目标之一是 脊椎动物是为了理解中枢神经系统是如何 控制运动神经元的激活以产生不同的运动 行为。作为运动行为基础的网络最容易 在鱼和两栖动物中进行研究，因为数量较少， 与哺乳动物相比，它们的神经元更大。这个 拟议中的实验旨在检查脊髓回路。 它控制着不同数量的轴向运动神经元 在金鱼中非常不同的运动行为--由 毛特纳细胞和正常游泳。 将使用细胞内记录和HRP染色技术 致： 1)检查被识别的中间神经元的输出连接 M细胞的脊髓网络。这些数据将提供必要的 已鉴定的中间神经元在脑内的作用 明确定义的脊椎动物运动行为的网络。 2)通过M-确定哪些神经元具有多突触活性 手机。这些数据将允许详细比较 M细胞网络对运动神经元和中间神经元的激活作用 还有游泳网络。 3)确定哪些脊髓中间神经元和运动神经元是活跃的 在虚构的金鱼游动过程中，作为与 游泳的M细胞网络和脊髓网络 其他脊椎动物。 4)直接确定单个中间神经元的突触输入 从两个网络接收，以评估脊椎 两者共有中间神经元。 5)研究游泳和M细胞网络之间的相互作用 通过在假想游泳过程中激发M细胞启动逃逸 这一集。 这些实验将提供有关中央的基本信息。 中枢运动神经元激活的调控机制 金鱼。因为之前的工作表明在 脊椎动物脊椎运动系统的组织 这些结果可能为我们提供对以下机制的一般性见解 脊椎动物运动神经元的控制，包括人类。

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.