Testing the roles of motoneuron membrane currents for behaviorally adequate motor output by targeted genetic manipulations of an identified flight motoneuron in Drosophila

中枢神经回路模式输出的产生取决于单个神经元的突触连通性和固有的膜特性。运动神经元是中枢模式产生回路和肌肉之间的中继站。运动神经元不仅仅是网络输入的追随者，它们的内在属性塑造了最终的电机输出。这个项目将使用果蝇中可用的遗传工具来揭开一个已识别的运动神经元突触输入整合和放电输出背后的离子机制。运动神经元的电流束将由原位膜片钳分析来描述。药理学和有针对性的遗传操作将被用来破译每个电流背后的基因(目标1)。第二，将通过原位钙成像实验(目标2)分析突触输入整合和树突状钙信号。这些数据将作为确定特定离子通道通过将选定运动神经元的定向遗传操作与完整行为动物的细胞外记录相结合来塑造运动神经元输出的作用的基础(目标3)。最后，众所周知，生物胺的调节可以调整运动模式以适应不断变化的需求。该项目将测试生物胺是否直接调节运动神经元离子通道，以及其功能后果是什么(目标4)。离子通道的高度保守性使得脊椎动物运动神经元的类似功能成为可能。了解正常的运动神经元功能是解决疾病期间或脊髓损伤后功能障碍的先决条件。

The generation of patterned output from central neural circuits depends on synaptic connectivity and intrinsic membrane properties of the individual neurons. Motoneurons are the relays station between central pattern generating circuitry and muscles. Motoneurons are not mere followers of network input, but their intrinsic properties shape the final motor output. This project will use genetic tools available in Drosophila to unravel the ionic mechanisms underlying synaptic input integration and firing output of an identified motoneuron. The motoneuron’s ionic current bouquet will be described by in situ patch clamp analysis. Pharmacological and targeted genetic manipulations will be used to decipher which genes underlie each current (objective 1). Second, synaptic input integration and dendritic calcium signaling will be analyzed by in situ calcium imaging experiments (objective 2). These data will serve as bedrock to determine the roles of specific ion channels for shaping motoneuron output by combining targeted genetic manipulations in selected motoneurons with extracellular recordings in intact behaving animals (objective 3). Finally, modulation by biogenic amines is known to adjust motor patterns to changing requirements. This project will test whether biogenic amines directly modulate motoneuron ion channels and what the functional consequences are (objective 4). The highly conserved nature of ion channels makes similar functions in vertebrate motoneurons likely. Understanding normal motoneuron function is a prerequisite for addressing malfunction during diseases or after spinal cord injury.