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Keeping the right time in space: importance of circadian clock and sleep for physiology and performance of astronauts.

Guo JH, Qu WM, Chen SG, Chen XP, Lv K, Huang ZL, Wu YL - Mil Med Res (2014)

Bottom Line: Circadian clocks and sleep evolved to adapt to Earth's environment, which is characterized by a 24-hour light-dark cycle.Changes in gravity load, lighting and work schedules during spaceflight missions can impact circadian clocks and disrupt sleep, in turn jeopardizing the mood, cognition and performance of orbiting astronauts.In this review, we summarize our understanding of both the influence of the space environment on the circadian timing system and sleep and the impact of these changes on astronaut physiology and performance.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006 China.

ABSTRACT
The circadian clock and sleep are essential for human physiology and behavior; deregulation of circadian rhythms impairs health and performance. Circadian clocks and sleep evolved to adapt to Earth's environment, which is characterized by a 24-hour light-dark cycle. Changes in gravity load, lighting and work schedules during spaceflight missions can impact circadian clocks and disrupt sleep, in turn jeopardizing the mood, cognition and performance of orbiting astronauts. In this review, we summarize our understanding of both the influence of the space environment on the circadian timing system and sleep and the impact of these changes on astronaut physiology and performance.

No MeSH data available.


Network diagram of the circadian clock, sleep, physiology and behavior in space. In space, a variety of environmental factors are involved in the regulation of the circadian clock and sleep. The circadian clock and sleep regulate each other. The alignment of the circadian clock and sleep is critical for physiology, behavior and performance. In turn, behavior and performance can feed back to affect the circadian clock and sleep.
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Fig1: Network diagram of the circadian clock, sleep, physiology and behavior in space. In space, a variety of environmental factors are involved in the regulation of the circadian clock and sleep. The circadian clock and sleep regulate each other. The alignment of the circadian clock and sleep is critical for physiology, behavior and performance. In turn, behavior and performance can feed back to affect the circadian clock and sleep.

Mentions: The circadian propensity for sleep increases during the sleep state, thus ensuring continued sleep despite the diminishing homeostatic need for it toward the end of the sleep cycle. Anatomical and functional evidence indicates that there is a relationship between the SCN and the sleep-wake system. The SCN has relatively modest projections into the VLPO and orexin neurons [19–21]. However, the major output is directed toward the adjacent subparaventricular zone and the dorsomedial nucleus of the hypothalamus. Cell-specific lesions in the ventral subparaventricular zone or the dorsomedial nucleus of the hypothalamus disrupt the circadian rhythms of sleep and wakefulness, suggesting that neurons in these areas must relay this influence [22, 23]. Disruption of sleep-wake timing can lead to misalignment of rhythmicity in physiological variables. Sleep deprivation causes deterioration and a decrease in performance [24]. Insufficient or mistimed sleep can reduce the rhythmicity of clock-controlled genes [6, 25]. These facts suggest that the circadian clock and sleep mutually regulate each other at both the molecular and the physiological levels (Figure 1).Figure 1


Keeping the right time in space: importance of circadian clock and sleep for physiology and performance of astronauts.

Guo JH, Qu WM, Chen SG, Chen XP, Lv K, Huang ZL, Wu YL - Mil Med Res (2014)

Network diagram of the circadian clock, sleep, physiology and behavior in space. In space, a variety of environmental factors are involved in the regulation of the circadian clock and sleep. The circadian clock and sleep regulate each other. The alignment of the circadian clock and sleep is critical for physiology, behavior and performance. In turn, behavior and performance can feed back to affect the circadian clock and sleep.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4440601&req=5

Fig1: Network diagram of the circadian clock, sleep, physiology and behavior in space. In space, a variety of environmental factors are involved in the regulation of the circadian clock and sleep. The circadian clock and sleep regulate each other. The alignment of the circadian clock and sleep is critical for physiology, behavior and performance. In turn, behavior and performance can feed back to affect the circadian clock and sleep.
Mentions: The circadian propensity for sleep increases during the sleep state, thus ensuring continued sleep despite the diminishing homeostatic need for it toward the end of the sleep cycle. Anatomical and functional evidence indicates that there is a relationship between the SCN and the sleep-wake system. The SCN has relatively modest projections into the VLPO and orexin neurons [19–21]. However, the major output is directed toward the adjacent subparaventricular zone and the dorsomedial nucleus of the hypothalamus. Cell-specific lesions in the ventral subparaventricular zone or the dorsomedial nucleus of the hypothalamus disrupt the circadian rhythms of sleep and wakefulness, suggesting that neurons in these areas must relay this influence [22, 23]. Disruption of sleep-wake timing can lead to misalignment of rhythmicity in physiological variables. Sleep deprivation causes deterioration and a decrease in performance [24]. Insufficient or mistimed sleep can reduce the rhythmicity of clock-controlled genes [6, 25]. These facts suggest that the circadian clock and sleep mutually regulate each other at both the molecular and the physiological levels (Figure 1).Figure 1

Bottom Line: Circadian clocks and sleep evolved to adapt to Earth's environment, which is characterized by a 24-hour light-dark cycle.Changes in gravity load, lighting and work schedules during spaceflight missions can impact circadian clocks and disrupt sleep, in turn jeopardizing the mood, cognition and performance of orbiting astronauts.In this review, we summarize our understanding of both the influence of the space environment on the circadian timing system and sleep and the impact of these changes on astronaut physiology and performance.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006 China.

ABSTRACT
The circadian clock and sleep are essential for human physiology and behavior; deregulation of circadian rhythms impairs health and performance. Circadian clocks and sleep evolved to adapt to Earth's environment, which is characterized by a 24-hour light-dark cycle. Changes in gravity load, lighting and work schedules during spaceflight missions can impact circadian clocks and disrupt sleep, in turn jeopardizing the mood, cognition and performance of orbiting astronauts. In this review, we summarize our understanding of both the influence of the space environment on the circadian timing system and sleep and the impact of these changes on astronaut physiology and performance.

No MeSH data available.