Table 1.

Percentage of time spent in wakefulness, REM sleep, and non-REM sleep and mean numbers of non-REM sleep onsets

	Spontaneous sleep-waking during the dark period (n = 6)	Spontaneous sleep-waking during the light period (n = 6)	Sleep deprivation in the light period (n = 6), experiment 1	Recovery after sleep deprivation (n = 6), experiment 1
Wakefulness (%)	91.2 ± 3.4**	27.1 ± 2.6*	94.4 ± 1.4**	11.24 ± 1.36*
REM sleep (%)	2 ± 0.71*	16 ± 1.67	0	16.78 ± 2.39
Non-REM sleep (%)	6.8 ± 2.9**	57.7 ± 2.04*	5.6 ± 1.4**	72.1 ± 2.5*
Mean numbers of non-REM sleep onsets (n)	4 ± 0.4*	9 ± 0.5*	54 ± 4.6*	14 ± 0.5*

Shown is the percentage of time spent in wakefulness, REM sleep, and non-REM sleep and mean numbers of non-REM sleep onsets for rats that were allowed spontaneous sleep-waking behavior during either the dark period (n = 6) or during the light period (n = 6), rats subjected to sleep deprivation during the light period (n = 6), and rats that were allowed recovery sleep after the sleep deprivation in the light (n = 6). Percentage of sleep-waking stages and the numbers of non-REM sleep onsets were calculated for a 1 h recording period before the rats were killed. ANOVA indicated significant effect of experimental condition for percentage of wakefulness (F_(3,20) = 356.1; p < 0.001), percentage of non-REM sleep (F_(3,20) = 238.7; p < 0.001) and percentage of REM sleep (F_(2,15) = 22.9; p < 0.001). ANOVA also indicated significant effect of experimental conditions on the numbers of non-REM sleep onsets (F_(3,20) = 21.7; p < 0.001). *Significantly different from all other groups; **significantly different from the light-sleep and recovery sleep rats, p < 0.050 (Newman–Keuls test).