Fig. 1
Photo-depolarization of the RIS neuron inhibits locomotion. a Maximum intensity projection showing single-cell GFP expression in RIS. The pharynx expressing mCherry is shown in magenta. Scale bar = 100 µm. Inset: Enlarged head region. Arrowhead: RIS axonal branch region. Scale bar = 25 µm. b Mean locomotion speed before, during, and after RIS::ChR2 photoactivation (blue bar). Data: mean ± SEM; n animals, cultivated with or without ATR, as indicated. c Kymographic representation of bending angles along the spine of a single animal (top: head, bottom: tail, blue to red scale encodes the ventral to dorsal bending). Scale bar is 5 s, blue bar indicates illumination. d Analysis of anterior or posterior body elongation during RIS photoactivation, demarcated by a dot painted on the body of the animal (pictogram: blue paint; dotted lines represent entire body (orange), head (white), or tail (gray) lengths along body mid line) in comparison to whole-body analysis. Boxplot with Tukey whiskers; comparisons are to the no light condition (red asterisks) or between body regions (black asterisks). e Fraction of reversals larger than one body length after mechanical stimulation to the head region during and after RIS photoactivation. Each animal was tested five times during both conditions (N = 40). f Frequency of long and short (shorter or longer than 1 s or 2.5 s, respectively) stops and reversals was compared in wild-type animals, as well as in animals lacking RIS due to expression of the apoptosis-inducer EGL-1. Boxplot with Tukey whiskers. n = number of animals. ***p ≤ 0.001; *p ≤ 0.05; statistical significance tested by one-way ANOVA with Tukey Multiple Comparison test in d and Wilcoxon matched pairs test in e, as well as by unpaired T test in f
