Sleep and wake profiles on day 8 after inducing rostromedial tegmental nucleus (RMTg) lesions with ibotenic acid.

(A) Diagrammatic drawing of lesion extent with ibotenic acid in the total 13 lesioned animals whose electroencephalograms (EEGs) were successfully collected after 8 days (RL84, RL116, RL140, RL142, RL162, RL164, RL183, and RL170, n = 8), 16 days (RL140, RL142, RL164, RL170, RL150, RL154, RL187, and RL194, n = 8), 25 days (RL116, RL164, RL183, RL187, RL194, and RL118, n = 6), and 8 days following 6-hour sleep deprivation (RL162, RL164, RL183, and RL170, n = 4) of lesions. The lesioned rats were numbered with the same color characters as the closed curves. The bilateral shaded areas indicate the RMTg area. (B) Photographs of representative coronal sections from a control (left) and a lesioned (right) rat by NeuN staining. The parts with red circles show the location of the RMTg. IPN, interpeduncular nucleus; ml, medial lemniscus. (C) Hourly amount of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep and wakefulness. (D) Total sleep–wake amount during the 9-hour dark period (19:00–04:00 hours), the subsequent 12-hour period (04:00–16:00 hours) and the 3-hour light period (16:00–19:00 h). (E–I) Sleep–wake architecture during 04:00 to 16:00 hours. Mean duration (E) and total episode numbers (F) of NREM and REM sleep and wakefulness; episode spectrum of NREM (G) and REM (H) sleep; transitions between S (NREM sleep), W (wakefulness), and R (REM sleep) stages (I). (J) Hourly slow-wave activity (SWA) (expressed as percentage of delta power [0.5–4 Hz] in NREM sleep per hour) of NREM sleep. *p < 0.05, **p < 0.01 versus controls. Control (n = 9); lesion (n = 8). The horizontal filled and open bars on the x-axes indicate the 12-hour dark period and the 12-hour light period, respectively. Underlying data can be found in S1 Data.