Autonomic regulation across sleep and wake during an Antarctic overwintering

📖 Top 20% JournalJan 13, 2026Scientific reports

Changes in automatic body control during sleep and wake in people staying over winter in Antarctica

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗OA ↗

Abstract

Heart rate variability measurements in 13 crewmembers showed changes in autonomic regulation associated with prolonged isolation and the polar night.

A decrease in parasympathetic regulation was observed during wakefulness as isolation duration increased.
Parasympathetic activity increased during sleep despite prolonged isolation.
During the polar night, parasympathetic activity during sleep decreased.
These changes in autonomic regulation may reflect adaptations to extreme environmental conditions.

AI simplified

Isolated, confined and extreme environments like Antarctic overwinterings present significant challenges to human psychophysiological adaptation. While previous evidence suggests that such conditions affect autonomic response, the extent to which human physiology adapts, in particular, the sleep-wake cycle and circadian rhythms, remains unclear. To assess the impact of prolonged isolation and the polar night on autonomic nervous system activity, we conducted an observational and longitudinal study at Belgrano II Argentine Antarctic station over a year-long campaign. Heart rate variability, a measure of cardiac autonomic modulation, was computed in 13 crewmembers over 24-hour periods every two months. Analysis revealed a decrease in parasympathetic regulation during wakefulness and an increase during sleep, in association with the increasing duration of isolation. At the same time, parasympathetic activity during sleep decreased during the polar night, suggesting a distinct seasonal effect. These findings offer novel insights into how isolation and the polar night influence autonomic regulation. Understanding these physiological adaptations is crucial for developing effective countermeasures to mitigate stress-related health issues in extreme environments.

Full Text

Full text is available at the source.

View full text (HTML) ↗View full text (PDF) ↗View full text (PDF) ↗