Motor pattern selection from a multifunctional motor circuit

这一提议的长期目标是在细胞水平上确定不同的外在调节机制 输入从构成行为基础的多功能神经网络中选择不同的运动模式。总而言之， 对于动物来说，神经调节使单个运动回路能够产生许多不同的活动模式，从而 产生不同的行为。这种网络的多功能特性在很大程度上来自于行动 它可以改变神经元的细胞和突触特性。这些物质是 由感觉神经元、体液神经元和投射神经元释放，以影响这些网络。到目前为止，人们对此知之甚少 关于特定的外在调节通路如何从多功能运动模式中选择特定的运动模式 网络。这个问题将使用一个定义明确的模型系统来解决，即孤立的螃蟹胃 神经系统，其中所有相关的神经元、突触和细胞膜特性都可以被识别 并被操控。具体地说，(1)由新发现的外源性物质触发的独特的咀嚼运动模式 调制途径将被表征，并与先前研究的两种模式进行比较 感官通路。(2)这将包括识别调节这一动作的中间投射神经元， 包括潜在的细胞和突触机制。这将有助于建立一个新的细胞水平 关于不同的外部输入是否通过以下方式从同一网络引发不同的电机输出的模型 激活相同、重叠或不同组的投射神经元。(3)依赖国家及国家- 不同外部输入的重叠或顺序激活的独立后果也将 将被确定，以及(4)不同的共同释放的发射器在这些进程中发挥的作用。这 该提案旨在结合细胞神经生理学、药理学和解剖学方法来 阐明从多功能网络中选择运动模式的一般原则。这将为我们提供指导 在更复杂和更难接近的哺乳动物神经系统中进行的可比性研究。因为 所有动物的网络活动都有相同的组织原则，这项工作也将促进更好的 了解导致行为异常或丧失的网络功能障碍，例如发生在 脊髓损伤、中风或调节状态改变的后果，如吸毒后。

The long-term goal of this proposal is to determine, at the cellular level, how different extrinsic modulatory inputs select distinct motor patterns from multifunctional neural networks that underlie behavior. In all animals, neuromodulation enables single motor circuits to produce many different activity patterns, thereby producing distinct behaviors. The multifunctional character of such networks derives largely from the actions of modulatory transmitters which alter the cellular and synaptic properties of neurons. These substances are released by sensory, humoral and projection neurons to influence these networks. Thus far, little is known about how specific extrinsic modulatory pathwaysselect a particular motor pattern from a multifunctional network. This issue will be addressed using a well-defined model system, the isolated crabstomatogastric nervous system, in which all of the relevant neurons, synapses and membrane properties can be identified and manipulated. Specifically, (1) the distinct chewing motor pattern triggered by a newly identified extrinsic modulatory pathway will be characterized and compared with the patterns elicited by two previously studied sensory pathways. (2) This will include identifying the intervening projection neurons that mediate this action, including the underlying cellular and synaptic mechanisms. This will help establish a new cellular-level model regarding whether distinct extrinsic inputs elicit different motor outputs from the same network by activating the same, overlapping or different sets of projection neurons. (3) The state-dependent and state- independent consequences from the overlapping or sequential activation of distinct extrinsic inputs will also be determined, as will (4) the roles played by distinct co-releasedtransmitters in these processes. This proposal aims to combine cellular neurophysiological, pharmacological and anatomical approaches to elucidate general principles about motor pattern selection from multifunctional networks. This will guide comparable studies in the more complex and less accessible mammalian nervous system. Because the same organizing principles underlie network activity in all animals, this work will also facilitate a better understanding of network dysfunction that produces aberrant or loss of behavior, such as occurs as a consequence of spinal cord injury, stroke or altered modulatory states such as after drug addiction.