Propofol dose-dependently increases the consolidated immobility. Mean ± SEM total time “sleep” (A) and “sleep” bout length (B) per 15 min during the 6-h propofol (PPF) or vehicle (VEH) treatment (horizontal bar, zeitgeber time [ZT] 0 to 6) and the 6 h period after treatment (ZT 7 to 12) is shown for all three doses of propofol and vehicle. Sleep is defined as the immobility for a minimum of 5 min. (C) Mean ± SEM total time “sleep” bout length per 6 h is shown for the 6-h propofol treatment and withdrawal periods. Gray bars correspond to times during which flies were flipped to and from tubes containing propofol. Significant differences between the four groups are indicated by asterisks, *P < 0.05, **P < 0.005, ***P < 0.0005, one-way ANOVA, Tukey pairwise comparisons. Data are derived from the same flies depicted in figure 1.