Sir2 acts in the mushroom body α/β-neurons to promote ethanol tolerance. A, Compressed z-stack image of an adult brain immunostained for mCherry (driven in the 17D-GAL4 pattern, green) and the presynaptic protein Bruchpilot (Brp; magenta). B, C, Sedation sensitivity (B) and sedation tolerance (C) of flies expressing the tetanus toxin light chain (TeTx) in the 17D pattern with or without MB-GAL80 to block mushroom body expression (n = 8). D, E, Sedation sensitivity (D) and sedation tolerance (E) of flies expressing Sir2 RNAi in the 17D pattern in the mushroom bodies, with and without MB-GAL80 (n = 15). Error bars indicate the SE. *p < 0.05, **p < 0.01.