The high-frequency component of heart rate variability during extended wakefulness is closely associated with the depth of the ensuing sleep in C57BL6 mice.
This study aimed to test the hypothesis that, during extended wakefulness, parasympathetic activity is associated with the depth of the subsequent recovery sleep in mice. Fourteen male C57BL/6 mice were implanted with electrodes for sleep recording. Continuous spectral analysis was performed on the electroencephalogram (EEG) to obtain theta power (6-9Hz) and delta power (0-4Hz), as well as the R-R interval signals in order to quantify the high-frequency power (HF) and normalized low-frequency power (LF%) that are used to assess parasympathetic and sympathetic activity, respectively. All animals underwent a sleep deprivation experiment and a control experiment (6-h intervention and 1-h recovery period) on two separate days. During sleep deprivation, HF and theta power during wakefulness were significantly higher than during the control wakefulness after the second hour and first hour, respectively. During recovery non-rapid eye movement sleep, there was a rebound in sleep time and delta power as well as an elevation in HF relative to control post-intervention sleep. Both the rise in HF and theta power during extended wakefulness were found to be positively correlated with the delta power rebound. Furthermore, the HF change during extended wakefulness was also correlated with the amount of sleep loss and the enhancement of waking theta power. Our finding suggests that waking parasympathetic activity intimately reflects the cumulative sleep pressure, suggesting a potential role to be an autonomic marker for sleep propensity.
Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Sleep Research Center, National Yang-Ming University, Taipei, Taiwan; Department of Education and Research, Taipei City Hospital, Taipei, Taiwan; Research Center for Adaptive Data Analysis, National Central University, Taoyuan, Taiwan.
T B J
TB
Kuo
Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Sleep Research Center, National Yang-Ming University, Taipei, Taiwan.
C T
CT
Lai
Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Sleep Research Center, National Yang-Ming University, Taipei, Taiwan; Neurological institute, Taipei Veterans General Hospital, Taipei, Taiwan.
C Y
CY
Chen
Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Sleep Research Center, National Yang-Ming University, Taipei, Taiwan.
Y C
YC
Yang
Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan; Sleep Research Center, National Yang-Ming University, Taipei, Taiwan; Department of Education and Research, Taipei City Hospital, Taipei, Taiwan. Electronic address: cchyang@ym.edu.tw.
C C H
CC
Yang
D000818:Animals; D001921:Brain / Q000503:physiopathology*; D003700:Delta Rhythm / Q000502:physiology; D004195:Disease Models, Animal; D004569:Electroencephalography; D006339:Heart Rate / Q000502:physiology*; D008297:Male; D008810:Mice, Inbred C57BL; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000503:physiopathology; D013826:Theta Rhythm / Q000502:physiology; D014851:Wakefulness / Q000502:physiology*
autonomic nervous system; heart rate variability; parasympathetic; sleep propensity; theta power; vagal