ANALYSIS OF INTERNEURONS AND MOTOR NEURONS

这个拟议项目的长期目标是理解人们有多紧张 系统控制移动。躯体运动神经元通常用于更多的 不仅是一个动作，而且可以在各种空间和时间中被激活 模式。一般说来，运动神经元是由一群前运动神经元驱动的。 中间神经元。运动前中间神经元是如何组织和激活的 产生不同的运动模式？是构成图案的神经元吗？ 用于一种行为的发电机，涉及其他电机的产生 回应是什么？如果是这样的话，一组神经元通过什么机制连接 共同服从一种运动功能被重组以参与另一种运动功能 运动模式？为了解决这些问题，我们将集中讨论 中枢神经系统内中间神经元和运动神经元的组织 软体动物Tritonia diomedea，作为模式系统。我们的实验方法 分为三个方面。使用细胞内录音，发射 已确定的运动前中间神经元和运动神经元的模式将是 在三种不同的行为中定量描述：游泳， 条件反射的撤退，还有进食。这些行为中的每一个都涉及一个 共同的运动神经元池以三种不同的模式激活。一个 第二系列实验侧重于细胞和突触机制 用于模式生成，包括i)突触的网络分析 中间神经元和中间神经元之间的连通性和整合特性 运动神经元，ii)对该运动系统的感觉输入路径的分析， 以及(Iii)识别运动网络内的调节位点。 最后，中间神经元和运动神经元的网络将被重建 通过数字计算机模拟来提供对相互作用和 细胞和突触特性在多发性脑脊髓炎的发生中的作用， 复杂的运动模式。这些实验应该揭示出 适用于更复杂系统的电机系统组织 在这种情况下，这种水平的细胞分析是不可能的。

The long term goal of the proposed project is to understand how nervous systems control movement. Somatic motor neurons are commonly used in more than one movement and can be activated in a variety of spatial and temporal patterns. In general, motor neurons are driven by a population of premotor interneurons. How are the premotor interneurons organized and activated to yield different motor patterns? Are the neurons which comprise the pattern generator for one behavior involved in the generation of other motor responses? If so, by what mechanisms can a set of neurons connected together to subserve one motor function be reorganized to participate other motor patterns? To address these questions we will concentrate on the organization of interneurons and motor neurons within the CNS of the mollusc, Tritonia diomedea, as a model system. Our experimental approach is divided into three areas. Using intracellular recordings, the firing patterns of identified premotor interneurons and motor neurons will be characterized quantitatively during three different behaviors: swimming, reflexive withdrawals, and feeding. Each of these behaviors involves a common pool of motor neurons activated in three different patterns. A second series of experiments focuses on cellular and synaptic mechanisms for pattern generation and includes i) a network analysis of the synaptic connectivity between and integrative properties of the interneurons and motor neurons, ii) analysis of sensory input pathways to this motor system, and (iii) identification of modulatory sites within the motor network. Finally the network of interneurons and motor neurons will be reconstructed by digital computer simulation to provide insights into the interaction and role of cellular and synaptic properties in the generation of multiple, complex motor patterns. These experiments should uncover principles of motor system organization which will be applicable to more complex systems in which this level of cellular analysis is not possible.