NREM3 sleep disrupts the brain-periphery hemodynamic coupling

This study investigates the coupling strength between low-frequency peripheral and cerebral hemodynamics among young, healthy volunteers, with concurrent acquisition of peripheral NIRS, brain fMRI, and EEG across wake and NREM sleep. The results document a strong positive coupling between low-frequency peripheral and cerebral hemodynamics during all stages except deep sleep (NREM3). Collectively, our results demonstrate that systemic physiology remains a dominant source of variability in brain hemodynamics both during resting wakefulness and light NREM sleep. However, deep NREM3 sleep may be an exception to this phenomenon implicative of its noteworthy role in optimal restoration of cerebral vasomotion.