title: Power spectrum analysis and heart rate variability in Stage 4 and REM sleep: evidence for state-specific changes in autonomic dominance.
abstract: The present study investigated autonomic activity during NREM and REM sleep stages and wakefulness by spectral analysis of heart rate variability. The results demonstrated that NREM sleep in humans was characterized by a widely different autonomic activation pattern than REM sleep: high parasympathetic activity was found in NREM, while REM was characterized by attenuated vagal tone, and augmented sympathetic activity. The overall pattern during wakefulness showed an intermediate position between NREM and REM patterns; parasympathetic activity was lower than in NREM and higher than in REM, with an opposite trend for sympathetic activity.
authors.affiliation: Sleep Laboratory and Department of Physiology, Technion, Israel Institute of Technology, Haifa, Israel.
authors.initials: I
authors.lastname: Berlad
authors.initials: A
authors.lastname: Shlitner
authors.initials: S
authors.lastname: Ben-Haim
authors.initials: P
authors.lastname: Lavie