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Sleep- and circadian-dependent modulation of REM density
Sat Bir S Khalsa1, Deirdre A Conroy, Jeanne F Duffy
1Division of Sleep Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA. khalsa@hms.harvard.edu
Journal of Sleep Research
|March 1, 2002
Summary
Rapid eye movement (REM) density increases during sleep, independent of circadian rhythm. Maximum REM density occurs late in sleep when circadian influence is also notable.
Area of Science:
- Sleep Science
- Chronobiology
- Neuroscience
Background:
- Rapid eye movement (REM) density, a measure of eye movement frequency during REM sleep, typically increases throughout a sleep episode.
- The influence of the circadian cycle on REM density has not been extensively studied.
Purpose of the Study:
- To investigate the circadian modulation of REM density.
- To determine how REM density is affected by both sleep duration and circadian phase.
Main Methods:
- Utilized data from a forced desynchrony protocol with 20 sleep opportunities across the circadian cycle.
- Analyzed polysomnographically recorded REM sleep episodes to evaluate REM density.
- Examined REM density in relation to time within the sleep opportunity and circadian phase.
Main Results:
- REM density significantly increased over the course of the sleep episode, irrespective of circadian phase.
- A significant circadian modulation of REM density was observed specifically in the final third of the sleep episode.
- Peak REM densities occurred when the latter part of sleep coincided with the wake-maintenance zone.
Conclusions:
- Sleep-dependent increases in REM density are dominant.
- Circadian modulation of REM density is apparent, particularly in the later stages of sleep.
- REM density is highest during periods of low sleep pressure, coinciding with circadian influences.
Keywords:
Non-programmatic
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