Figure 2.

(a) Total time (min, mean ± SEM) spent in each state in control mice (wild type) (n = 5), H₁R^−/− mice (n = 4), H₁R^−/−; OX₁R^−/− mice (n = 4) and OX₁R^−/−;OX₂R^−/− mice (n = 5). W, awake; NR, non-rapid eye movement (REM) sleep; R, REM sleep. The graphs summarize the data recorded during the 12 h dark period. (B) Episode duration (s ± SEM) spent in each state in control mice, H₁R^−/− mice, H₁R^−/−;OX₁R^−/− mice and OX₁R^−/−;OX₂R^−/− mice. W, awake; NR, non-REM sleep; R, REM sleep. OX₁R^−/−; OX₂R^−/− mice show significantly shorter wakefulness and NREM sleep episodes during dark period. Mice with other genotypes did not show any abnormality in sleep/wake states. *P < 0.001. The graphs summarize the data recorded during the 12 h dark period.