Effects of 6-h sleep deprivation (SD) on nonREM sleep EEG slow wave activity (SWA) in (A) wild-type (WT) and (B) 5-HT2cR KO mice. Mean (± SEM) nonREM sleep SWA values following sleep deprivation (POST-SD: circles) and in the PRE-SD period (squares) are expressed as a % of the mean 24-h nonREM SWA values obtained in the baseline day of sleep/wake recording. * Significant difference between PRE-SD and POST-SD values (5-HT2cR KO: PRE-SD vs. POST-SD × Hour: F = 4.42, p < .0001, SNK, p < .05; WT:PRE-SD vs. POST-SD × Hour: F = 2.11, p < .04, SNK, p < .05).