Sensory control of a motor sequence

摘要 动物从环境中收集感官信息，并利用它在众多信息中进行选择 他们可以执行的行为。使它们能够检测、比较和识别的确切神经回路 跨空间和时间结合感觉刺激来组织运动序列仍然未知。 果蝇的梳理行为是一种感觉驱动的运动序列。我们建议使用 光遗传学工具和行为分析来识别相关的感觉神经元和电路 用于苍蝇梳理序列的启动和进展。修饰是与生俱来的——基础 梳理毛发的能力是与生俱来的，依赖于基因特定的神经连接，因此 可通过遗传筛选进行解剖。但构成的动作顺序 梳理动作灵活：大概率会出现扫头、蹭前腿的情况 早期，清洁后身体部位的后腿子程序稍后会发生，但是 这些动作的确切顺序并不固定。苍蝇利用更新的感官线索来改变 扫腿的轨迹、清洁回合的持续时间以及移除的动作顺序 碎片的不同分布有效。 对神经系统如何组织可靠但适应性的深入机械理解 运动序列将解决动物如何利用大量运动的更大问题 感觉数据，它们如何平衡精确运动的需要和需要 根据上下文修改它，以及有限数量的神经元如何产生不同的阵列 动物行为。神经回路基序构成了所有神经系统的基本计算单元 系统。定义完成控制电机的感官比较的电路 更简单的系统（例如苍蝇梳理）中的序列将为理解提供一个模板 所有大脑如何实现相似的功能。

Abstract Animals collect sensory information from their environment and use it to select among the many behaviors they can perform. The exact neural circuits that enable them to detect, compare, and combine sensory stimuli across space and time to organize motor sequences remain unknown. Grooming behavior in Drosophila is a sensory-driven motor sequence. We propose to use optogenetic tools and behavioral analysis to identify the sensory neurons and circuits relevant for initiation and progression of the fly grooming sequence. Grooming is innate – the basic capacity to groom is inborn, relying on genetically-specified neural connections, and therefore accessible to dissection by genetic screens. But the sequence of the actions that constitute grooming is flexible: there is a high probability that head sweeps and front leg rubs will occur early and that back leg subroutines to clean the posterior body parts will happen later, but the exact order of these movements is not fixed. Flies use updating sensory cues to modify the trajectory of leg sweeps, the duration of cleaning bouts, and the order of movements to remove different distributions of debris effectively. A deep mechanistic understanding of how the nervous system organizes reliable but adaptive motor sequences will address the larger questions of how animals make use of a flood of sensory data, how they balance the need to exercise a movement precisely with the need to modify it based on context, and how a limited number of neurons produce the diverse array of animal behaviors. Neural circuit motifs form the basic computational units of all nervous systems. Defining the circuits that accomplish sensory comparisons that control a motor sequence in a simpler system such as fly grooming will provide a template for understanding how similar functions are achieved in all brains.