Molecular-neural basis for motor patterning of vocal-acoustic signals

了解大脑如何控制行为是神经科学的一个主要目标。所有的行为动作，包括走路、唱歌，甚至是让人专注于一页文字的微小眼球运动，最终都取决于大脑中运动神经元对肌肉的激活。动物所能做出的各种各样的动作引出了一个问题：不同行为背后的运动神经元有多大的不同？回答这个问题的一个策略是比较驱动不同行为的神经元。现代硬骨鱼在发声能力方面是冠军，它们表现出快速、精确定时的声音脉冲。这里提出的研究使用鱼类作为模型系统，将发声运动神经元群体与那些模式化非发声运动行为的群体进行比较：取决于鳍运动的运动，以及由鱼类用于通信和主动感知水生环境的修饰肌肉细胞产生的电信号。该项目将确定运动神经元中分子，遗传和生理特性共享的程度，这些行为在时间模式上不同，例如，快速（声音和电）与慢速（鳍运动）。首席研究员将继续招募来自不同背景的优秀男女学生，包括代表性不足的少数民族，并在行为，神经和分子水平的分析方面对他们进行培训。更具体地说，分子，遗传学和神经生理学方法在几个模式系统中的鱼类将被用来解决以下问题：1）可以解释相似的一组基因产物，一组共同的发声运动神经元字符（目标1）之间的远亲物种的发声运动行为的神经生理模式？ 2)发声运动神经元是否采用了一种“分子工具箱”，与非发声运动神经元不同，后者表现出较低程度的同步性和时间精确性，在这种情况下，是用于运动的胸肌运动系统（目的2）？ 3)发声运动神经元是否与非发声运动神经元共享一个“分子工具箱”，表现出相当程度的同步性、时间精确性和快速放电，在这种情况下，非发声运动神经元是用于主动感知水生环境中物体的神经元系统（目标3）？通过用神经药理学验证补充大规模基因表达研究，这些目标将确定基因表达模式如何决定神经生物学和行为表型，在这种情况下，这些表型决定不同的运动功能。

Understanding how the brain controls behavior is a major goal in neuroscience. All behavioral actions, including those as different as walking, singing, even tiny eye movements that allow one to focus on a page of text, ultimately depend on the activation of muscles by motor neurons in the brain. The remarkable range of actions that animals are capable of begs the question: how different are the motor neurons underlying different behaviors? One strategy for answering this is to compare neurons driving different behaviors. Modern bony fishes are champions in the ability to generate vocalizations that exhibit rapid, precisely timed sound pulses. The studies proposed here use fish as model systems to compare vocal motor neuron populations to those that pattern non-vocal motor behaviors: locomotion that depends on fin movement, and electric signaling generated by modified muscle cells that are used by fish for communication and active sensing of the aquatic environment. The project will determine the extent to which molecular, genetic and physiological properties are shared in motor neurons driving these behaviors that differ in their temporal patterning, for example, fast (vocal and electric) vs. slow (fin movement). The Principal Investigator will continue to recruit a talented population of men and women students from diverse backgrounds, including underrepresented minorities, and train them in behavioral, neural, and molecular levels of analysis. More specifically, molecular, genetic and neurophysiological methods in several model systems among fishes will be used to address the following questions: 1) Can similarities in the neurophysiological patterning of vocal motor behavior between distantly related species be explained by a similar set of gene products that underlies a shared set of vocal motor neuron characters (Aim 1)? 2) Do vocal motor neurons employ a "molecular toolkit" distinct from that of non-vocal motor neurons exhibiting lower degrees of synchrony and temporal precision, in this case the pectoral motor system for locomotion (Aim 2)? 3) Do vocal motor neurons employ a shared "molecular toolkit" with that of non-vocal motor neurons exhibiting comparable degrees of synchronicity, temporal precision and rapid firing, in this case the electromotor system that is used for active sensing of objects in the aquatic environment (Aim 3)? By complementing large-scale gene expression studies with neuro-pharmacological validation, these aims will identify how patterns of gene expression determine neurobiological and behavioral phenotypes, in this case those determining divergent motor functions.