Fig. 2.
Effect of modafinil on sleep latency. Dbh +/− and Dbh −/− mice were placed in observation chambers, injected with vehicle or modafinil (6.25, 12.5, or 25 mg/kg, i.p.) 4 hours later, and observed until the onset of sleep. Shown is latency to sleep following the injection. * P < 0.05, ** P < 0.001 compared to vehicle control for that genotype. † P < 0.01 compared to Dbh +/− mice for that dose.