toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Prayag, A.S.; Najjar, R.P.; Gronfier, C. url  doi
openurl 
  Title Melatonin suppression is exquisitely sensitive to light and primarily driven by melanopsin in humans Type Journal Article
  Year 2019 Publication Journal of Pineal Research Abbreviated Journal J Pineal Res  
  Volume 66 Issue 4 Pages (down) e12562  
  Keywords Human Health; melatonin suppression; melanopic illuminance  
  Abstract INTRODUCTION: Light elicits a range of non-visual responses in humans. Driven predominantly by intrinsically photosensitive retinal ganglion cells (ipRGCs), but also by rods and/or cones, these responses include melatonin suppression. A sigmoidal relationship has been established between melatonin suppression and light intensity, however photoreceptoral involvement remains unclear. METHODS AND RESULTS: In this study, we first modelled the relationships between alpha-opic illuminances and melatonin suppression using an extensive dataset by Brainard and colleagues. Our results show that 1) melatonin suppression is better predicted by melanopic illuminance compared to other alpha-opic illuminances, 2) melatonin suppression is predicted to occur at levels as low as ~1.5 melanopic lux (melanopsin-weighted irradiance 0.2 muW/cm(2)), 3) saturation occurs at 305 melanopic lux (melanopsin-weighted irradiance 36.6 muW/cm(2)). We then tested this melanopsin-weighted illuminance response model derived from Brainard and colleagues' data and show that it predicts equally well melatonin suppression data from our laboratory, although obtained using different intensities and exposure duration. DISCUSSION: Together, our findings suggest that melatonin suppression by monochromatic lights is predominantly driven by melanopsin, and that it can be initiated at extremely low melanopic lux levels in experimental conditions. This emphasizes the concern of the non-visual impacts of low light intensities in lighting design and light-emitting devices. This article is protected by copyright. All rights reserved.  
  Address Lyon Neuroscience Research Center, Integrative Physiology of the Brain Arousal Systems, Waking team, Inserm UMRS 1028, CNRS UMR 5292, Universite Claude Bernard Lyon 1, Universite de Lyon, F-69000, Lyon, France  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0742-3098 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:30697806 Approved no  
  Call Number GFZ @ kyba @ Serial 2186  
Permanent link to this record
 

 
Author Phillips, A.J.K.; Vidafar, P.; Burns, A.C.; McGlashan, E.M.; Anderson, C.; Rajaratnam, S.M.W.; Lockley, S.W.; Cain, S.W. url  doi
openurl 
  Title High sensitivity and interindividual variability in the response of the human circadian system to evening light Type Journal Article
  Year 2019 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc Natl Acad Sci U S A  
  Volume 116 Issue 24 Pages (down) 12019-12024  
  Keywords Human Health; circadian rhythms; light sensitivity; circadian disruption; melatonin suppression; evening light  
  Abstract Before the invention of electric lighting, humans were primarily exposed to intense (>300 lux) or dim (<30 lux) environmental light-stimuli at extreme ends of the circadian system's dose-response curve to light. Today, humans spend hours per day exposed to intermediate light intensities (30-300 lux), particularly in the evening. Interindividual differences in sensitivity to evening light in this intensity range could therefore represent a source of vulnerability to circadian disruption by modern lighting. We characterized individual-level dose-response curves to light-induced melatonin suppression using a within-subjects protocol. Fifty-five participants (aged 18-30) were exposed to a dim control (<1 lux) and a range of experimental light levels (10-2,000 lux for 5 h) in the evening. Melatonin suppression was determined for each light level, and the effective dose for 50% suppression (ED50) was computed at individual and group levels. The group-level fitted ED50 was 24.60 lux, indicating that the circadian system is highly sensitive to evening light at typical indoor levels. Light intensities of 10, 30, and 50 lux resulted in later apparent melatonin onsets by 22, 77, and 109 min, respectively. Individual-level ED50 values ranged by over an order of magnitude (6 lux in the most sensitive individual, 350 lux in the least sensitive individual), with a 26% coefficient of variation. These findings demonstrate that the same evening-light environment is registered by the circadian system very differently between individuals. This interindividual variability may be an important factor for determining the circadian clock's role in human health and disease.  
  Address Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia sean.cain@monash.edu  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0027-8424 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:31138694 Approved no  
  Call Number IDA @ intern @ Serial 2521  
Permanent link to this record
 

 
Author Pilz, L.K.; Levandovski, R.; Oliveira, M.A.B.; Hidalgo, M.P.; Roenneberg, T. url  doi
openurl 
  Title Sleep and light exposure across different levels of urbanisation in Brazilian communities Type Journal Article
  Year 2018 Publication Scientific Reports Abbreviated Journal Sci Rep  
  Volume 8 Issue 1 Pages (down) 11389  
  Keywords Human Health; Sleep  
  Abstract Quilombos are settlements originally founded by Africans and African descendants (Quilombolas) in remote parts of Brazil to escape slavery. Due to individual histories, Quilombos nowadays exhibit different states of industrialisation, making them ideal for studying the influence of electrification on daily behaviour. In a comparative approach, we aimed to understand whether and how human sleep changes with the introduction of artificial light. We investigated daily rest-activity-rhythms and sleep-patterns in the Quilombolas' by both wrist actimetry and the Munich ChronoType Questionnaire (MCTQ; the results of these two instruments correlated highly). Seven communities (MCTQ: N = 213/actimetry: N = 125) were compared in this study. Light exposure, phase of activity, sleep timing and duration differ across communities with various levels of urbanisation and histories of access to electricity. People living without electricity and those, who acquired it only very recently on average sleep earlier than those in more urbanised communities (mid-sleep about 1 hour earlier); sleep duration tends to be longer. Our results and those of others show that use of electricity and modern lifestyles have changed sleep behaviour. To understand the consequences of these changes for health, further studies are warranted.  
  Address Visiting Professor at UFRGS/CAPES, Porto Alegre, RS, Brazil. roenneberg@lmu.de  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:30061685 Approved no  
  Call Number GFZ @ kyba @ Serial 1968  
Permanent link to this record
 

 
Author Oh, J.H.; Yoo, H.; Park, H.K.; Do, Y.R. url  doi
openurl 
  Title Analysis of circadian properties and healthy levels of blue light from smartphones at night Type Journal Article
  Year 2015 Publication Scientific Reports Abbreviated Journal Sci Rep  
  Volume 5 Issue Pages (down) 11325  
  Keywords human health  
  Abstract This study proposes representative figures of merit for circadian and vision performance for healthy and efficient use of smartphone displays. The recently developed figures of merit for circadian luminous efficacy of radiation (CER) and circadian illuminance (CIL) related to human health and circadian rhythm were measured to compare three kinds of commercial smartphone displays. The CIL values for social network service (SNS) messenger screens from all three displays were higher than 41.3 biolux (blx) in a dark room at night, and the highest CIL value reached 50.9 blx. These CIL values corresponded to melatonin suppression values (MSVs) of 7.3% and 11.4%, respectively. Moreover, smartphone use in a bright room at night had much higher CIL and MSV values (58.7 ~ 105.2 blx and 15.4 ~ 36.1%, respectively). This study also analyzed the nonvisual and visual optical properties of the three smartphone displays while varying the distance between the screen and eye and controlling the brightness setting. Finally, a method to possibly attenuate the unhealthy effects of smartphone displays was proposed and investigated by decreasing the emitting wavelength of blue LEDs in a smartphone LCD backlight and subsequently reducing the circadian effect of the display.  
  Address Department of Chemistry, Kookmin University, Seoul 136-702, Republic of Korea  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:26085126 Approved no  
  Call Number LoNNe @ christopher.kyba @ Serial 1196  
Permanent link to this record
 

 
Author Takemura, Y.; Ito, M.; Shimizu, Y.; Okano, K.; Okano, T. url  doi
openurl 
  Title Adaptive light: a lighting control method aligned with dark adaptation of human vision Type Journal Article
  Year 2020 Publication Scientific Reports Abbreviated Journal Sci Rep  
  Volume 10 Issue 1 Pages (down) 11204  
  Keywords Human Health; Vision; Lighting  
  Abstract Light exposure before sleep causes a reduction in the quality and duration of sleep. In order to reduce these detrimental effects of light exposure, it is important to dim the light. However, dimming the light often causes inconvenience and can lower the quality of life (QOL). We therefore aimed to develop a lighting control method for use before going to bed, in which the illuminance of lights can be ramped down with less of a subjective feeling of changes in illuminance. We performed seven experiments in a double-blind, randomized crossover design. In each experiment, we compared two lighting conditions. We examined constant illuminance, linear dimming, and three monophasic and three biphasic exponential dimming, to explore the fast and slow increases in visibility that reflect the dark adaptation of cone and rod photoreceptors in the retina, respectively. Finally, we developed a biphasic exponential dimming method termed Adaptive Light 1.0. Adaptive Light 1.0 significantly prevented the misidentification seen in constant light and effectively suppressed perceptions of the illuminance change. This novel lighting method will help to develop new intelligent lighting instruments that reduce the negative effect of light on sleep and also lower energy consumption.  
  Address The Smart Life Science Institute, ACROSS, Waseda University, Tokyo, Japan. okano@waseda.jp  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:32641723; PMCID:PMC7343865 Approved no  
  Call Number GFZ @ kyba @ Serial 3050  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: