睡眠與自主神經的互動
Kuo T. B. J., Shaw F. Z., Lai C. J., and Yang C. C. H.* (2008) Asymmetry in sympathetic and vagal activities during sleep-wake transitions. Sleep 31(3):311-320
Study Objectives: To explore the role of autonomic nervous system in initiation of sleep-wake transitions.
Design: Changes in cardiovascular variabilities during sleep-wake transitions of adult male Wistar-Kyoto rats on their normal daytime sleep were analyzed.
Interventions: A 6 hour daytime sleep-wakefulness recording session was performed.
Measurements and Results: Electroencephalogram and electromyogram (EMG) signals were subjected to continuous power spectral analysis, from which mean power frequency of the electroencephalogram (MPF) and power of the EMG were quantified. Active waking (AW), quiet sleep (QS), and paradoxical sleep (PS) were defined every 8 s according to corresponding MPF and EMG power. Continuous power spectral analysis of R-R intervals was performed to quantify its high-frequency power (HF, 0.6-2.4 Hz), low-frequency power (0.06-0.6 Hz) to HF ratio (LF/HF). MPF exhibited two phases of change during AW-QS and QS-AW transitions: a slowly changing first phase followed by a rapidly changing second phase. HF increased linearly with the decrease of MPF during the first phase of AW-QS transition whereas LF/HF increased linearly with the increase of MPF during the first phase of QS-AW transition. However, the LF/HF was not correlated with the HF. The MPF and HF exhibited only a rapidly changing phase during QS-PS transition. The LF/HF declined transiently during the QS-PS transition, followed by a sustained increase in PS.
Conclusions: The parasympathetic activity before falling asleep and the sympathetic activity before waking up change coincidentally with EEG frequency, and may respectively contain the messages of sleeping and waking drives.
睡眠與自主神經互動在疾病上的變化
Kuo, T. B. J. and Yang, C. C. H.* (2005) Sleep-related changes in cardiovascular neural regulation in spontaneously hypertensive rats. Circulation 112:849-854
BACKGROUND: Sleep has significant effects on cardiovascular neural regulation. The aim of this study is to explore the possible change in sympathetic vasomotor activity and baroreflex sensitivity associated with spontaneous hypertension during each stage of the sleep-wake cycle.
METHODS AND RESULTS: Polysomnographic analysis was performed in freely moving spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) during their normal daytime sleep. Continuous spectral analyses of electroencephalogram and electromyogram were performed to define active waking, quiet sleep, and paradoxical sleep. Low-frequency power of the arterial pressure variability (BLF) was quantified to provide an index of sympathetic vasomotor activity. Spontaneous baroreflex sensitivity was assessed (1) by the slopes of the regression lines of the mean arterial pressure and R-R intervals pairs that ascended (BrrA) or descended (BrrD) successively and (2) by the magnitudes of the arterial pressure and R-R intervals transfer functions in the high-frequency (BrrHF) or low-frequency (BrrLF) ranges. SHR had significantly higher mean arterial pressure during each of the sleep-wake states. Although the values of BLF, BrrA, BrrD, BrrHF, and BrrLF in SHR did not differ from those of WKY during active waking, SHR had a significantly higher BLF and lower BrrA, BrrD, BrrHF, and BrrLF compared with WKY during quiet sleep and paradoxical sleep.
CONCLUSIONS: SHR had enhanced sympathetic vasomotor activity but attenuated baroreflex sensitivity during sleep although each phenomenon was not evident when awake.