Hypnograms and sleep and waking patterns. Upper panel: representative 24-h hypnograms from a Kcna2 null (KO), heterozygous (HZ), and wild-type (WT) pup at P17. White and black bars indicate the light and dark period, respectively. W, waking; NREM, NREM sleep; REM, REM sleep. Middle and lower panels: 24-h sleep and waking patterns and 12-h sleep and waking amounts (mean ± SEM) in Kcna2 KO, HZ, and WT pups at P17. *, p < 0.05 (Tukey's test).