A, Comparison between CB1 KO and wt mice (N = 6 in each group) in the time spent in NREM sleep, awake, and in REM sleep across the circadian period during baseline recordings. Data in each epoch were normalized to the total recording time to yield the percent of time spent in each state. B, Comparison of NREM architecture between genotypes. Graphs show data pertaining to the number and duration of NREM bouts. C, Comparison between genotypes for measures of delta power during NREM across the circadian cycle. Data represent the results of power spectral analysis of ECoG waveforms recorded during NREM sleep normalized to the total power across the power spectrum (0.5–20 Hz) for each time bin. For all graphs, black bars/circles represent data from wt mice, and white bars/circles represent data from CB1 KO mice. In time series graphs, the white background indicated the light photoperiod and the grey background denotes the dark photoperiod. Data represent the means ± SEM of each genotype within the specified time bin or photoperiod. For A and C, data were grouped in 3 hr bins. In B, each bar represents a 12 hr (one photoperiod) bin. Significant 3-way interactions between photoperiod, time of day, and genotype are denoted with stars (★). Significant main effects of genotype are denoted with pound signs (#). Significant main effects of photoperiod are denoted with a dagger (†). Significant pair-wise comparisons are denoted with asterisks (*).