Motor pattern selection from a multifunctional motor circuit

这项提议的长期目标是在细胞水平上确定不同的外源性调节 输入从作为行为基础的多功能神经网络中选择不同的运动模式。在所有 在动物中，神经调节使单个运动回路能够产生许多不同的活动模式， 产生不同的行为。这种网络的多功能性主要来自于 神经元的细胞和突触特性的调节性递质。这些物质 由感觉、体液和投射神经元释放以影响这些网络。到目前为止， 关于特定的外在调节途径如何从多功能的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良好的模型系统来解决， 神经系统，其中所有相关的神经元，突触和膜特性都可以识别 被操纵具体而言，（1）由新发现的外源性刺激触发的独特咀嚼运动模式， 调节途径的特点，并与模式引起的两个先前研究 感觉通路(2)这将包括识别介导这一动作的介入投射神经元， 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 关于不同的外在输入是否会从同一网络中引出不同的运动输出的模型， 激活相同、重叠或不同的投射神经元集合。(3)依赖国家和国家- 来自不同外在输入的重叠或顺序激活的独立结果也将 确定，将（4）在这些过程中不同的共同释放的transmitters所扮演的角色。这 该提案旨在将细胞神经生理学、药理学和解剖学方法联合收割机， 阐明从多功能网络中选择运动模式的一般原则。这将指导 在更复杂和更难接近的哺乳动物神经系统中进行的类似研究。因为 同样的组织原则在所有动物的网络活动的基础上，这项工作也将促进更好的 理解网络功能障碍，产生异常或行为丧失，如发生在 脊髓损伤、中风或调节状态改变（如药物成瘾后）的结果。

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.