Fig. 7.

Response to wake-promoting therapeutics in DAT knock-out (−/−; open bars) and wild-type (filled bars) mice. Data are reported as the cumulative change in time awake (mean ± SEM) 5 hr after treatment relative to corresponding baseline 24 hr earlier. Two-way ANOVA indicated significant genotype × treatment interaction in comparisons of individual pharmacological treatments versus vehicle (p < 0.05, all treatments).VEH, 0.25% methylcellulose vehicle;METH, methamphetamine; GBR, GBR12909.¹p < 0.001;²p < 0.025 between groups;³p < 0.002 relative to vehicle; Student's t test. Sample sizes (+/+, −/−): vehicle (9, 8); methamphetamine, 2 mg/kg (14, 10); GBR12909, 20 mg/kg (14, 6); modafinil, 90 mg/kg (10, 9) and 300 mg/kg (14, 6); caffeine, 2.5 mg/kg (10, 8), 10 mg/kg (12, 7), and 20 mg/kg (8, 0).