Cardiac autonomic nervous system activity during presleep wakefulness and Stage 2 NREM sleep

Citation
Hj. Burgess et al., Cardiac autonomic nervous system activity during presleep wakefulness and Stage 2 NREM sleep, J SLEEP RES, 8(2), 1999, pp. 113-122
Citations number
31
Categorie Soggetti
Neurosciences & Behavoir
Journal title
JOURNAL OF SLEEP RESEARCH
ISSN journal
09621105 → ACNP
Volume
8
Issue
2
Year of publication
1999
Pages
113 - 122
Database
ISI
SICI code
0962-1105(199906)8:2<113:CANSAD>2.0.ZU;2-9
Abstract
Previous research has found that cardiac parasympathetic nervous system (PN S) activity increases and cardiac sympathetic nervous system (SNS) activity decreases during night-time sleep. This study aimed to examine in greater detail the time course of these changes in cardiac autonomic nervous system (ANS) activity. In the week prior to the experimental night, nine subjects maintained a constant sleep-wake schedule and experienced an adaptation ni ght. Each subject's experimental night consisted of 2 h of presleep wakeful ness, followed by a night of sleep, commencing at each subject's normal sle ep onset time. One hundred and twenty beat blocks of presleep wakefulness a nd stable Stage 2 non-rapid eye movement (NREM) sleep across the night were selected. SNS activity was assessed using pre-ejection period, the amplitu de of the T-wave in the ECG and the 0.1 Hz peak from the spectral analysis of the EGG. PNS activity was assessed using respiratory sinus arrhythmia (s pectral analysis). Heart rate and respiratory rate were also measured. The results indicated a progressive decrease in SNS activity throughout sleep a nd a rise in PNS activity during the first half of the normal sleep period. The changes in PNS activity were similar, while the changes in SNS activit y were altered, compared with a previous study in which stage of sleep was not controlled. This indicates a likely sleep stage influence on SNS activi ty, but not on cardiac PNS activity. These results are consistent with the concept of a primarily circadian, but not sleep, influence on PNS activity, and primarily a sleep, but not circadian, influence on SNS activity.