Fig. 1: PVP neurons promote forward movement and inhibit backward movement.

a Schematic representation of C. elegans PVP neurons within an adult hermaphrodite, adapted from WormAtlas⁵⁴. A pair of PVP somas located near the tail, with cross processes (green lines) extending anteriorly along the ventral midline (orange dashed line), terminating in the head nerve ring (NR). For clarity, the tail schematic is rotated 90 degrees counterclockwise. b PVP morphology before and after blue-light ablation (8.3 mW/cm²). GFP-highlighted PVP somas (white arrow, control group (+ PVP)) were eliminated after ablation (- PVP). This experiment was independently repeated more than three times (with 3–5 animals per trial), yielding consistent results. The white dashed lines outline the worms. Scale bar, 20 μm. c Five representative trajectories from 3 min free movement sessions before (+ PVP) and after (- PVP) PVP ablation. The gray diamonds indicate the starting positions of the worms. d Representative velocity in control (black, + PVP) and ablated (gray, - PVP) animals. e Raster plots displaying individual locomotion velocity for animals without (+ PVP) and with (- PVP) the ablation of PVP (n = 18 animals per group), biological replicates. f, g Analysis of the proportions of forward and backward locomotion in (e). Following PVP ablation, there was a decrease in forward movement and an increase in backward locomotion (p < 0.001, p < 0.001). h, i Measurement of velocity, duration, and initiation frequency across different motor states after the ablation of PVP in (e) (p < 0.001, p < 0.001, p < 0.001, p = 0.4079). j Raster plots displaying individual locomotion velocity for animals without (n = 16 animals) and with histamine (n = 15 animals), biological replicates. k, l Analysis of the proportions of forward and backward locomotion in (j). Following histamine application, there was a decrease in the velocity of forward movement and an increase in the initiation frequency of backward locomotion (p < 0.001, p < 0.001). m, n Quantification of velocity, duration, and initiation frequency across different motor states after the application of histamine in (j) (p < 0.001, p < 0.001, p < 0.001, p = 0.3098). Animals #, the animal number used in the experiments. ***p < 0.001; ns, not significant by two-tailed Student’s t test. Error bars, SEM. Source data are provided as a Source Data file.