Fig. 6

Activation of DNp09 descending neurons leads to freezing. a Schematic of experimental set-up for CsChrimson stimulation and stimulation protocol. Test flies supplemented with retinal (n = 80) and control flies raised in normal food (n = 72). b Fraction of flies freezing. Dashed lines indicate light stimulation. c Fraction of flies freezing aligned on light activation (retinal n = 800, control n = 720 stimulation events). d Stimulus-triggered speed profile (average ± s.e.m.) aligned on light presentation for stimulations that induced freezing (dark blue, n = 492), stimulations that did not (light blue, n = 308) and control (black, n = 720). e Probability ( + 95% CI) of jumping at light offset for control and test flies (black and red bars). Probability of jumping at light offset for stimulation events of test flies that induced freezing and events that did not (dark and light blue bars). f Probability of freezing to red light stimulation as a function of pre-stimulation speed (r² = 0.87, p = 0.007). X-error bars show s.d. for speed sampled within each interval and Y-error bars show 95% CI. g Probability of freezing for DNp09 > CsChrimson flies (n = 50 for each condition) tested at different speeds (number of stimulation events for very high, high and low were 403, 674 and 593, respectively). *** denotes p < 0.001