Figure 2.

Effect of sucrose concentration and caffeine on nighttime sleep. (A) Graphic of experimental design used to habituate flies to the DAM environment. White and black rectangles denote the light (ZT 0–12) and dark (ZT 12–24) periods, respectively. Food was swapped from the standard Drosophila medium to sucrose diets at the end of day 1. The effect of the various sucrose diets ± 0.5 mg/mL caffeine on nighttime sleep is shown for (B) Canton-S, (C) w¹¹¹⁸, and (D) iso31 females. Values represent average ± SEM. n = 15–17 flies per diet. When applicable, independent trials are shown separately using open or closed symbols. Significance of trials denoted with open or closed symbols is represented by gray or black asterisks, respectively. *p ≤ .05, **p ≤ .01, ***p ≤ .001, ****p ≤ .0001. ZT, zeitgeber time.