Data from: Resolving coiled shapes reveals new reorientation behaviors in C. elegans

We exploit the reduced space of C. elegans postures to develop a novel tracking algorithm which captures both simple shapes and also self-occluding coils, an important, yet unexplored, component of 2D worm behavior. We apply our algorithm to show that visually complex, coiled sequences are a superposition of two simpler patterns: the body wave dynamics and a head-curvature pulse. We demonstrate the precise ΩΩ-turn dynamics of an escape response and uncover a surprising new dichotomy in spontaneous, large-amplitude coils; deep reorientations occur not only through classical ΩΩ-shaped postures but also through larger postural excitations which we label here as δδ-turns. We find that omega and delta turns occur independently, suggesting a distinct triggering mechanism, and are the serpentine analog of a random left-right step. Finally, we show that omega and delta turns occur with approximately equal rates and adapt to food-free conditions on a similar timescale, a simple strategy to avoid navigational bias.

我们利用秀丽隐杆线虫（C. elegans）姿态的降维空间，开发了一种新型追踪算法，该算法可同时捕捉简单形体与自遮挡卷曲行为——这是二维蠕虫行为中一类重要却尚未被探索的组成部分。我们借助该算法证实，视觉上复杂的卷曲序列实则是两种更简单模式的叠加：躯体波动动力学与头部曲率脉冲。我们揭示了逃逸反应中精准的Ω形转向动力学，并在自发大振幅卷曲行为中发现了一种出人意料的全新二分现象：深度重定向不仅可通过经典的Ω形姿态实现，还可通过我们在此定义为δ形转向的更大幅度姿态激发来完成。我们发现Ω形与δ形转向的发生相互独立，这提示二者存在截然不同的触发机制，且二者是随机左右转向的蛇行运动类似模式。最后，我们证实Ω形与δ形转向的发生频率大致相当，且二者在无食物条件下的适应时长远趋一致，这是一种规避导航偏差的简单策略。