Extended Data Fig. 4: Calcium signals in hook flexion axons.

a, Example trial of calcium imaging of hook flexion axons on the treadmill in which the animal did not transition often between moving and not moving, resulting in a high cross-correlation between predicted and measured calcium signals. b, Median predicted and measured calcium signals during active and passive movement bouts on the platform (N = 5 flies, n = 264–536 bouts in total); bouts are at least 0.5 s in duration. Distributions, kernel density estimations; boxes, IQR and median, whiskers extend up to 1.5 × IQR. c, Example of calcium imaging of hook flexion axons without the treadmill. d, Cross-correlation between predicted and measured calcium signals per trial at a time lag of zero (N = 8 flies, n = 58 trials in total). Black line, median; black dot, trial shown in c. e, Predicted and measured calcium signals aligned to the transitions into and out of movement (N = 8 flies). Signals are baseline subtracted (mean from −0.5 to 0 s). Thin lines, animal means; thick lines, mean of means; shadings, s.e.m. f, Example calcium imaging of hook flexion axons (second driver line) during behavior on the treadmill. g, Same as d but for the second hook flexion driver line imaged on the treadmill (N = 6 flies, n = 64 trials in total). h, Same as e but for the second hook flexion driver line imaged on the treadmill (N = 6 flies). Movement includes walking and grooming. i, Example of calcium imaging of hook flexion axons (second driver line) without the treadmill. j, Same as d but for the second hook flexion driver line imaged without the treadmill (N = 7 flies, n = 40 trials in total). k, Same as e but for the second hook flexion driver line imaged without the treadmill (N = 7 flies).