Figure 6.

EEG theta activity and the number of NREM sleep episodes during the sleep deprivation. (A) Mean waking EEG spectra during the last 90 min of the four 6-h sleep deprivations (SDep) starting at ZT0 (orange), -6 (yellow), -12 (green), or -18 (blue line). For comparison the mean spectral profile for waking calculated of the 48-h baseline is depicted (gray line). Baseline spectral profiles did not differ among the 4 sleep-deprivation groups. (B) Theta peak power (left) and frequency (right panel) did differ among the 4 sleep deprivations (post hoc Tukey; P < 0.05; peak theta power: ZT0 = ZT18 > ZT18 = ZT12 = ZT6; frequency: ZT12 = ZT18 > ZT6 = ZT0). Color coding for sleep-deprivation timing as in panel A and ZT times indicated refer to the sleep-deprivation start. (C) The number of NREM sleep episodes obtained during the ZT6-12 sleep deprivation was highest (post hoc Tukey; P < 0.05; number of episodes: ZT6 > ZT0 = ZT12 = ZT18). See panel B for details.