Effects of light on human circadian rhythms, sleep and mood

Somnologie - Schlafforschung und Schlafmedizin, Journal Year: 2019, Volume and Issue: 23(3), P. 147 - 156

Published: Aug. 20, 2019

Humans live in a 24-hour environment, which light and darkness follow diurnal pattern. Our circadian pacemaker, the suprachiasmatic nuclei (SCN) hypothalamus, is entrained to solar day via pathway from retina synchronises our internal biological rhythms. Rhythmic variations ambient illumination impact behaviours such as rest during sleep activity wakefulness well their underlying processes. Rather recently, availability of artificial has substantially changed especially evening night hours. This may increase risk developing rhythm sleep-wake disorders (CRSWD), are often caused by misalignment endogenous rhythms external light-dark cycles. While exact relationship between CRSWD remains be established, nocturnal been shown alter humans. On other hand, can also used an effective noninvasive therapeutic option with little no side effects, improve sleep,mood general well-being. article reviews current state knowledge regarding effects on rhythms, sleep, mood.

Language: Английский

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Melanopic illuminance defines the magnitude of human circadian light responses under a wide range of conditions

Journal of Pineal Research, Journal Year: 2020, Volume and Issue: 69(1)

Published: April 5, 2020

Abstract Ocular light drives a range of nonvisual responses in humans including suppression melatonin secretion and circadian phase resetting. These are driven by intrinsically photosensitive retinal ganglion cells (ipRGCs) which combine intrinsic, melanopsin‐based, phototransduction with extrinsic rod/cone‐mediated signals. As result this arrangement, it has remained unclear how best to quantify predict its effects. To address this, we analysed data from nineteen different laboratory studies that measured suppression, resetting and/or alerting wide array stimulus types, intensities durations or without pupil dilation. Using newly established SI‐compliant metrics ipRGC‐influenced light, show melanopic illuminance consistently provides the available predictor for human system. In almost all cases, is able fully account differences sensitivity stimuli varying spectral composition, acting drive track variations illumination characteristic those encountered over civil twilight (~1‐1000 lux equivalent daylight illuminance). Collectively, our demonstrate widespread utility as metric predicting impact environmental illumination. therefore provide strong support use basis guidelines seek regulate exposure benefit health inform future lighting design.

Language: Английский

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Circadian Photoentrainment in Mice and Humans

Biology, Journal Year: 2020, Volume and Issue: 9(7), P. 180 - 180

Published: July 21, 2020

Light around twilight provides the primary entrainment signal for circadian rhythms. Here we review mechanisms and responses of mouse human systems to light. Both utilize a network photosensitive retinal ganglion cells (pRGCs) expressing photopigment melanopsin (OPN4). In both species action spectra functional expression OPN4 in vitro show that has λmax close 480 nm. Anatomical findings demonstrate there are multiple pRGC sub-types, with some evidence mice, but little humans, regarding their roles regulating physiology behavior. Studies non-human primates rods cones project can modulate light pRGCs. Such an integration signals enables detect dim light, higher intensities intermittent exposure, whilst measures bright over extended periods time. Although photoreceptor similar, sensitivity thresholds differ markedly between mice humans. Mice entrain at approximately 1 lux few minutes, humans require high irradiance (>100's lux) long duration (>30 min). The basis this difference remains unclear. As our exposure is highly dynamic, because interactions complex difficult model, attempts develop evidence-based lighting enhance very challenging. A way forward will be define artificial natural "real world" where intensity, duration, spectral quality, time day, history age each assessed.

Language: Английский

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Individual differences in light sensitivity affect sleep and circadian rhythms

SLEEP, Journal Year: 2020, Volume and Issue: 44(2)

Published: Oct. 13, 2020

Abstract Artificial lighting is omnipresent in contemporary society with disruptive consequences for human sleep and circadian rhythms because of overexposure to light, particularly the evening/night hours. Recent evidence shows large individual variations photosensitivity, such as melatonin suppression, due artificial light exposure. Despite emerging body research indicating that effects on vary dramatically across individuals, recommendations appropriate exposure real-life settings rarely consider effects. This review addresses recently identified links among traits, example, age, sex, chronotype, genetic haplotypes, hallmarks, based laboratory field studies. Target biological mechanisms differences sensitivity include occurring within retina downstream, central clock. also highlights there are wide gaps uncertainty, despite growing awareness shape physiology. These (1) why do certain traits differentially affect influence rhythms; (2) what translational value populations typically exposed at night, night shift workers; (3) magnitude population-based studies? Collectively, current findings provide strong support considering when defining optimal specifications, thus allowing personalized solutions promote quality life health.

Language: Английский

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The Lighting Environment, Its Metrology, and Non-visual Responses

Frontiers in Neurology, Journal Year: 2021, Volume and Issue: 12

Published: March 4, 2021

International standard CIE S 026:2018 provides lighting professionals and field researchers in chronobiology with a method to characterize light exposures respect non-visual photoreception responses. This defines five spectral sensitivity functions that describe optical radiation for its ability stimulate each of the α-opic retinal photoreceptor classes contribute effects humans via intrinsically-photosensitive ganglion cells (ipRGCs). The also recently published an open-access toolbox calculates all quantities ratios metrology photometric, radiometric photon systems, based on either measured (user-defined) spectrum or selected illuminants (A, D65, E, FL11, LED-B3) built into toolbox. For wide variety ecologically-valid conditions, melanopsin-based ipRGCs has been shown account responses, from shifting timing nocturnal sleep melatonin secretion regulating steady-state pupil diameter. Recent findings continue confirm photopigment melanopsin plays role visual may have significant influence brightness perception aspects spatial vision. Although knowledge concerning extent which rods cones interact driving is still growing, position statement used melanopic equivalent daylight (D65) illuminance preliminary guidance applying “proper at proper time” manipulate Further this approach awaited participants 2nd Workshop Circadian Neurophysiological Photometry (in Manchester, August 2019). new 026 enables traceable measurements formal, quantitative specification personal exposures, photic interventions designs. Here, we apply everyday sources including natural time series, range LED products and, using toobox, smartphone display screen. collection examples suggests ways variations content over day can be adopted strategies use support human health well-being.

Language: Английский

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Molecular Basis of the Beneficial Actions of Resveratrol

Archives of Medical Research, Journal Year: 2020, Volume and Issue: 51(2), P. 105 - 114

Published: Feb. 1, 2020

Language: Английский

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Melatonin’s neuroprotective role in mitochondria and its potential as a biomarker in aging, cognition and psychiatric disorders

Translational Psychiatry, Journal Year: 2021, Volume and Issue: 11(1)

Published: June 2, 2021

Abstract Melatonin is an ancient molecule that evident in high concentrations various tissues throughout the body. It can be separated into two pools; one of which synthesized by pineal and found blood, second present these tissues. Pineal melatonin levels display a circadian rhythm while tissue does not. For decades now, has been implicated promoting maintaining sleep. More recently, evidence indicates it also plays important role neuroprotection. The beginning our review will summarize this literature. As amphiphilic, pleiotropic indoleamine, both direct actions receptor-mediated effects. example, established effects as antioxidant free radical scavenger vitro animal models. This melatonin’s prominent mitochondria, reviewed next section. in, taken up by, concentrated powerhouse cell. Mitochondria are major source reactive oxygen species byproduct mitochondrial oxidative metabolism. final section summarizes potential aging psychiatric disorders. decline with age. declines individuals suffering from Melatonin’s ability to act neuroprotectant opens new avenues exploration for may treatment cases neurodegenerative disease.

Language: Английский

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Melanopic irradiance defines the impact of evening display light on sleep latency, melatonin and alertness

Communications Biology, Journal Year: 2023, Volume and Issue: 6(1)

Published: March 1, 2023

Evening light-emitting visual displays may disrupt sleep, suppress melatonin and increase alertness. Here, we control melanopic irradiance independent of display luminance colour, in 72 healthy males 4 h before habitual bedtime expose each them to one four levels (i.e., dim light, smartphone, tablet or computer screen illuminance) at a low high setting. Low light shortens the time fall asleep, attenuates evening suppression, reduces morning melatonin, advances onset decreases alertness compared light. In addition, observe dose-dependent increases sleep latency, reductions concentration delays as function irradiance-not so for subjective We identify an appropriate parameter mitigate unwanted effects use night. Our results help many people who sit front screens night asleep faster, feel sleepier, have more stable phase by spectrally tuning without compromising appearance.

Language: Английский

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ENLIGHT: A consensus checklist for reporting laboratory-based studies on the non-visual effects of light in humans

EBioMedicine, Journal Year: 2023, Volume and Issue: 98, P. 104889 - 104889

Published: Dec. 1, 2023

BackgroundThere is no consensus on reporting light characteristics in studies investigating non-visual responses to light. This project aimed develop a checklist for laboratory-based investigations the impact of physiology.MethodsA four-step modified Delphi process (three questionnaire-based feedback rounds and one face-to-face group discussion) involving international experts was conducted reach items be included checklist. Following process, resulting tested pilot phase with independent experts.FindingsAn initial list 61 related light-based interventions condensed final containing 25 items, based upon among (final n = 60). Nine were deemed necessary report regardless research question or context. A description each item provided accompanying Explanation Elaboration (E&E) document. The testing led minor textual clarifications E&E document.InterpretationThe ENLIGHT Checklist first consensus-based documenting ocular human studies. implementation will enhance by ensuring comprehensive documentation, enhancing reproducibility, enabling data aggregation across studies.FundingNetwork European Institutes Advanced Study (NETIAS) Constructive Thinking (CAT) programme; Sir Henry Wellcome Postdoctoral Fellowship (Wellcome Trust, 204686/Z/16/Z); Netherlands Organisation Health Research Development VENI fellowship (2020–09150161910128); U.S. Department Defense Grant (W81XWH-16-1-0223); National University Singapore (NUHSRO/2022/038/Startup/08); Foundation (NRF2022-THE004-0002).

Language: Английский

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Individual differences and diversity in human physiological responses to light

EBioMedicine, Journal Year: 2022, Volume and Issue: 75, P. 103640 - 103640

Published: Jan. 1, 2022

Exposure to light affects our physiology and behaviour through a pathway connecting the retina circadian pacemaker in hypothalamus - suprachiasmatic nucleus (SCN). Recent research has identified significant individual differences non-visual effects of light,mediated by this pathway. Here, we discuss fundamentals light. We propose set actions improve evidence database be more diverse: understanding systematic bias base, dedicated efforts recruit diverse participants, routine deposition sharing data, development data standards reporting guidelines.

Language: Английский

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