Fig. 5

a, b 3D rendering of y279-Gal4, UAS:Kaede expression in the habenula at 7 dpf in intact larvae (a) and after bilateral ablation of y279-expressing PT neurons (b). Arrow indicates habenular commissure present in intact larvae that is lost after bilateral PT ablation. Scale bar 20 µm. c, d Confocal projections of y279-Gal4;UAS:Kaede-expressing larvae following unilateral focal photoconversion of Kaede in the left (c) or right (d) rostral PT. Photoconverted Kaede in the red channel is saturated to facilitate visualization of PT projections. Scale bar 20 µm. e Net turn angle (mean of trials 2–4) for intact control larvae (N = 47) and after bilateral ablation of y279-expressing habenula neurons (N = 22). Larvae were classified as left-biased (gray) or right-biased (cyan) based on trial 1 (T1). Asterisk p < 0.001, d = 1.4, t test. f Total amount of turning for larvae in (e) during locomotion under baseline illumination (yellow) or dark-induced circling behavior (gray). g Net turn angle (mean of trials 1–4) in non-ablated controls (white, N = 47), and following unilateral ablation of the left (gray, N = 33) and right (cyan, N = 28) habenula nuclei, or following laser section of the habenular commissure (c) (N = 24). Asterisk p < 0.001, d = 0.90, t test. ^#p < 0.05, d = 0.73, one-sample t test to 0. h Representative confocal scan showing y279-labeled habenular commissure (arrow) in a control larva (top). Following ablation commissure is absent (bottom). Scale bar 20 µm. Error bars represent standard error of the mean. Box plots show median and quartiles with whiskers indicating 10–90%. Source data are provided as a Source Data file.