Behavioral probabilities and sample videos for \"Behavioral evidence for nested central pattern generator control of Drosophila grooming\"

Central pattern generators (CPGs) are neurons or neural circuits that produce periodic output without requiring patterned input. More complex behaviors can be assembled from simpler subroutines, and nested CPGs have been proposed to coordinate their repetitive elements, organizing control over different time-scales. Here, we use behavioral experiments to establish that Drosophila grooming may be controlled by nested CPGs. On a short time-scale (5-7 Hz), flies execute periodic leg sweeps and rubs. More surprisingly, transitions between bouts of head cleaning and leg rubbing are also periodic on a longer time-scale (0.3 - 0.6 Hz). We examine grooming at a range of temperatures to show that the frequencies of both oscillations increase – a hallmark of CPG control – and also that the two time-scales increase at the same rate, indicating that the nested CPGs may be linked. This relationship also holds when sensory drive is held constant using optogenetic activation, but the rhythms can decou...

中枢模式发生器（Central pattern generators, CPGs）是一类无需模式化输入即可产生周期性输出的神经元或神经环路。更为复杂的行为可由简单子程序组装而来，而嵌套式中枢模式发生器已被提出用于协调其重复组成单元，实现对不同时间尺度的调控。本研究通过行为学实验证实，果蝇（Drosophila）的理毛行为或许受嵌套式中枢模式发生器调控。在短时间尺度（5-7 Hz）下，果蝇会完成周期性的腿部扫动与擦拭动作。更令人意外的是，头部清洁与腿部擦拭回合间的转换在更长的时间尺度（0.3-0.6 Hz）下同样呈现周期性。我们通过在一系列温度下开展理毛行为观测，证实两种振荡的频率均会升高——这是中枢模式发生器调控的标志性特征——且两种时间尺度以相同速率增加，表明嵌套式中枢模式发生器之间可能存在关联。当通过光遗传激活（optogenetic activation）维持感觉驱动恒定时，该关联依然成立，但节律可发生解耦……