Ultradian sleep rhythms of lateral EEG, autonomic, and cardiovascular activity are coupled in humans

This study compared the dynamics of multiple systems during sleep with earlier results during waking rest. Three consecutive nights of data were collected from three healthy adults for 10 variables: left and right central EEGs; the nasal cycle (NC); beat-to-beat measures of CO, SV, HR, SBP, DBP, MAP, and hemoglobin-oxygen saturation. Time series analysis detected periods at 280-300, 215-275, 165-210, 145-160, 105-140, 70-100, and 40-65 min bins with the greatest spectral power in longer periods. We found significance across subjects with all parameters at 280-300, 105-140 (except left EEG power, left minus right EEG power, and HR), 70-100, and 40-65 min. Significant periods were reported earlier during waking for the NC, pituitary hormones, catecholamines, insulin, and cardiovascular function in five bins at 220-340, 170-215, 115-145, 70-100, and 40-65 min, with 115-145, 70-100, and 40-65 min common across all variables. These results suggest that lateral EEG power during sleep has a common pacemaker (the hypothalamus), or a mutually entrained pacemaker, with the cardiovascular and autonomic nervous systems (ANS), and that the waking ultradians of the neuroendocrine and fuel regulatory hormones may also be coupled to lateral EEG activity. Taken together these results present a new perspective for the Basic Rest-Activity Cycle and the physiology of the ANS-central nervous system during both waking and sleep.