Values (means ± S.E.M.) of different parameters are shown for each 2 h intervals of the L (09.00–21.00) and D (21.00–09.00) periods of the recovery (R1, filled circles) and base line (BL, empty circles): MA, motor activity; Thy, hypothalamic temperature. Values concerning sleep stages (Wake, NREM sleep (NREMS), REM sleep in the form of single (single REMS) and sequential (sequential REMS) episodes), the ratio of REMS to total sleep, levels of power density in the delta (0.75–4.0 Hz; band of the EEG during NREMS (NREMS-Delta)) are expressed as the percent fraction of each of the respective 2 h interval. Statistically significant comparisons are shown: treatment vs. BL (*, P<0.05).