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态与自遮挡盘绕行为——这是二维蠕虫行为中一项重要却尚未被探索的组成部分。我们将该算法应用于研究，证实视觉上复杂的盘绕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。我们解析了逃逸反应中精准的Ω形转向动力学，并在自发性大振幅盘绕行为中发现了一个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，还可通过我们在此命名为δ形转向的更大幅度姿态激发过程完成。我们发现Ω形转向与δ形转向独立发生，这提示二者存在截然不同的触发机制，且它们是蛇形运动中对应随机左右移步的类比行为。最后，我们证实Ω形转向与δ形转向的发生速率大致相当，且二者在无食物条件下的适应时长相近，这是一种能够有效规避导航偏差的简单策略。