PRESYNAPTIC CONTROL OF NEURAL NETWORK MODULATION

中枢神经系统中的离散神经网络 (CNS)对脊椎动物和无脊椎动物来说， 产生模式化的神经活动， 行为。 本提案的一个长期目标是了解 调节的细胞机制和功能后果 这些网络的输入来自CNS。 一个相关的目标是 在细胞水平上，了解这些输入的调制是如何 受到突触前影响的调节 这项建议的重点是调制幽门和胃 磨神经网络，位于口胃神经节（STG）的 螃蟹，巨蟹座。 电生理技术，基于 将STG网络神经元的体内记录与 进入STG的调节输入的轴突内记录，将被 用于实现以下目标。(1)描述单个轴突 影响这些网络，通过结合 轴突内染色填充和免疫细胞化学，然后确定 这些神经网络对轴突刺激的反应方式 很好地模仿了外源性应用它的发射器。(2)研究 这些轴突的局部影响，以及是否有明显的膜 这些轴突的特性或突触效应，在STG内。 然后 确定每一个如何塑造这些轴突调节幽门和 胃磨网络活性。(3)确定以下方面的活动和产出： 这些轴突在这个神经系统的其他地方，以确定是否 神经元可以同时使用不同的脉冲模式来影响 不同的神经网络 这些实验的结果将提供一个新的水平， 了解，以前无法获得的，关于个体神经元如何使用 调节性递质影响节律性活动的神经网络， 以及这种影响如何在终端附近进行局部调节， 输入. 这将有助于指导概念理解和实验 在类似但不太容易接近的脊椎动物系统中的方法。

Discrete neural networks, within the central nervous system (CNS) of both vertebrates and invertebrates, are responsible for generating the patterned neural activity that mediates rhythmic behaviors. A long-term goal of this proposal is to understand the cellular mechanisms and functional consequences underlying the modulation of these networks by inputs from within the CNS. A related goal is to understand, at the cellular level, how modulation by these inputs is regulated by presynaptic influences. This proposal focuses on modulation of the pyloric and gastric mill neural networks, located in the stomatogastric ganglion (STG) of the crab, Cancer borealis. Electrophysiological techniques, based on combining intra-somatic recordings of STG network neurons with intra-axonal recordings of modulatory inputs entering the STG, will be used to attain the following goals. (1) Characterize how individual axons influence these networks, identify the axon's transmitter by combining intra-axonal dye filling and immunocytochemistry, and then determine whether the way these networks respond to axon stimulation is well-mimicked by exogenous application of it's transmitter. (2) Study local influences on these axons, and whether there are distinct membrane properties or synaptic effects of these axons, within the STG. Then determine how each one shapes the way these axons modulate pyloric and gastric mill network activity. (3) Identify the activity and outputs of these axons elsewhere in this nervous system, to determine whether a neuron can simultaneously use different impulse patterns to influence different neural networks. The results of these experiments will provide a new level of understanding, previously unobtainable, about how individual neurons use modulatory transmitters to influence rhythmically active neural networks, and how this influence is locally regulated near the terminals of the input. This will help guide conceptual understanding and experimental approaches in the similar but less accessible, vertebrate systems.