Figure 1.
Recording brain activity in behaving flies. A, Brain-recording setup. B, Fly movement is quantified from a filmed experiment. Top: A pixel subtraction method defines fly movement. Bottom: Activity pattern for a sample fly during the day (white bar) and night (black bar). Movement scale is Δ pixels/frame. Threshold for inactivity is indicated by the red line. C, Left: Average minutes rest per hour (± SEM) for tethered female flies on an air-suspended ball (prepared for electrophysiology), for day (white) and night (black). n = 13 wild-type females. **p < 0.01 by t test comparison of means. Right: Average rest bout length (± SEM) for the same flie. *p < 0.05 by t test comparison of means. D, Rest bout distribution (average number of times each rest bout occurred per fly ± SEM for day and night). Longer rest bouts are more common at night. ***p < 0.001; **p < 0.01; *p < 0.05 by t test comparison of means. E, 30 s sample of LFP activity in a fly that has been inactive for over 5 min (black), with corresponding movement channel (blue) below the empirically set threshold (red line; see Materials and Methods). F, 30 s sample of LFP in an active fly (black), with corresponding movement traces (blue) above the empirically set threshold (red line).