Sojourn times and normalized transition rates in the steady phase (2001-7200 sec; ca. 30-120 min). The estimated mean of the average time spent between two jumps (sojourn time; s) in A) WAKE, B) NREM and C) REM sleep, and the normalized transition rates (relative rates compared to the transition rate of HC-VEH group, which is 1) D) from WAKE to NREM, E) from NREM to WAKE, F) from WAKE to REM, G) from REM to WAKE, H) from NREM to REM I) and from REM to NREM states. Each point (●) represents the mean values and the line segments show the 95% confidence interval surrounding them. Groups: home cage-chronic vehicle treatment (HC-VEH); home cage-chronic escitalopram treatment (HC-SSRI); REM sleep deprivation-chronic vehicle treatment (RD-VEH); REM sleep deprivation-chronic escitalopram treatment (RD-SSRI).