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Author (down) Evans, J.A.; Elliott, J.A.; Gorman, M.R. url  doi
openurl 
  Title Dim nighttime illumination accelerates adjustment to timezone travel in an animal model Type Journal Article
  Year 2009 Publication Current Biology : CB Abbreviated Journal Curr Biol  
  Volume 19 Issue 4 Pages R156-7  
  Keywords *Adaptation, Physiological; Animals; Behavior, Animal/physiology; Biological Clocks/*physiology; Circadian Rhythm/*physiology; Cricetinae; Humans; *Lighting; Mesocricetus; Mice; Motor Activity/physiology; Phodopus; *Photoperiod; Time Factors  
  Abstract Jetlag reflects a mismatch between local and circadian time following rapid timezone travel [1]. Appropriately timed bright light can shift human circadian rhythms but recovery is slow (e.g., 1-2 days per timezone). Most symptoms subside after resynchronization, but chronic jetlag may have enduring negative effects [2], including even accelerated mortality in mice [3]. Melatonin, prescription drugs, and/or exercise may help shift the clock but, like bright light, require complex schedules of application [1]. Thus, there is a need for more efficient and practical treatments for addressing jetlag. In contrast to bright daytime lighting, nighttime conditions have received scant attention. By incorporating more naturalistic nighttime lighting comparable in intensity to dim moonlight, we demonstrate that recovery after simulated jetlag is accelerated when nights are dimly lit rather than completely dark.  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0960-9822 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:19243688 Approved no  
  Call Number IDA @ john @ Serial 152  
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Author (down) Evans, J.A.; Carter, S.N.; Freeman, D.A.; Gorman, M.R. url  doi
openurl 
  Title Dim nighttime illumination alters photoperiodic responses of hamsters through the intergeniculate leaflet and other photic pathways Type Journal Article
  Year 2012 Publication Neuroscience Abbreviated Journal Neuroscience  
  Volume 202 Issue Pages 300-308  
  Keywords Animals; Biological Clocks/physiology; Circadian Rhythm/physiology; Cricetinae; Darkness; Data Interpretation, Statistical; Geniculate Bodies/*physiology; *Lighting; Male; Motor Activity/physiology; Phodopus; *Photoperiod; Visual Pathways/*physiology  
  Abstract In mammals, light entrains the central pacemaker within the suprachiasmatic nucleus (SCN) through both a direct neuronal projection from the retina and an indirect projection from the intergeniculate leaflet (IGL) of the thalamus. Although light comparable in intensity to moonlight is minimally effective at resetting the phase of the circadian clock, dimly lit and completely dark nights are nevertheless perceived differentially by the circadian system, even when nighttime illumination is below putative thresholds for phase resetting. Under a variety of experimental paradigms, dim nighttime illumination exerts effects that may be characterized as enhancing the plasticity of circadian entrainment. For example, relative to completely dark nights, dimly lit nights accelerate development of photoperiodic responses of Siberian hamsters transferred from summer to winter day lengths. Here we assess the neural pathways underlying this response by testing whether IGL lesions eliminate the effects of dim nighttime illumination under short day lengths. Consistent with previous work, dimly lit nights facilitated the expansion of activity duration under short day lengths. Ablation of the IGL, moreover, did not influence photoperiodic responses in animals held under completely dark nights. However, among animals that were provided dimly lit nights, IGL lesions prevented the short-day typical expansion of activity duration as well as the seasonally appropriate gonadal regression and reduction in body weight. Thus, the present data indicate that the IGL plays a central role in mediating the facilitative effects of dim nighttime illumination under short day lengths, but in the absence of the IGL, dim light at night influences photoperiodic responses through residual photic pathways.  
  Address Department of Psychology, University of California, San Diego, La Jolla, CA, USA. jevans@msm.edu  
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  ISSN 0306-4522 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:22155265; PMCID:PMC3578228 Approved no  
  Call Number IDA @ john @ Serial 87  
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Author (down) Dumont, M.; Lanctot, V.; Cadieux-Viau, R.; Paquet, J. url  doi
openurl 
  Title Melatonin production and light exposure of rotating night workers Type Journal Article
  Year 2012 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 29 Issue 2 Pages 203-210  
  Keywords Adult; Animals; Circadian Rhythm/*physiology; Humans; *Light; Melatonin/*analogs & derivatives/*biosynthesis/urine; Neoplasms/etiology; *Photoperiod; Risk Factors; Sleep/physiology; *Work; Work Schedule Tolerance  
  Abstract Decreased melatonin production, due to acute suppression of pineal melatonin secretion by light exposure during night work, has been suggested to underlie higher cancer risks associated with prolonged experience of night work. However, the association between light exposure and melatonin production has never been measured in the field. In this study, 24-h melatonin production and ambulatory light exposure were assessed during both night-shift and day/evening-shift periods in 13 full-time rotating shiftworkers. Melatonin production was estimated with the excretion of urinary 6-sulfatoxymelatonin (aMT6s), and light exposure was measured with an ambulatory photometer. There was no difference in total 24-h aMT6s excretion between the two work periods. The night-shift period was characterized by a desynchrony between melatonin and sleep-wake rhythms, as shown by higher melatonin production during work and lower melatonin production during sleep when working night shifts than when working day/evening shifts. Light exposure during night work showed no correlation with aMT6s excreted during the night of work (p > .5), or with the difference in 24-h aMT6s excretion between the two work periods (p > .1). However, light exposure during night work was negatively correlated with total 24-h aMT6s excretion over the entire night-shift period (p < .01). In conclusion, there was no evidence of direct melatonin suppression during night work in this population. However, higher levels of light exposure during night work may have decreased total melatonin production, possibly by initiating re-entrainment and causing internal desynchrony. This interpretation is consistent with the proposition that circadian disruption, of which decreased melatonin production is only one of the adverse consequences, could be the mediator between night shiftwork and cancer risks.  
  Address Chronobiology Laboratory, Center for Advanced Research in Sleep Medicine, Sacre-Coeur Hospital of Montreal, Montreal, Quebec, Canada. marie.dumont@umontreal.ca  
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  ISSN 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:22324558 Approved no  
  Call Number IDA @ john @ Serial 138  
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Author (down) Dominoni, D.M.; Goymann, W.; Helm, B.; Partecke, J. url  doi
openurl 
  Title Urban-like night illumination reduces melatonin release in European blackbirds (Turdus merula): implications of city life for biological time-keeping of songbirds Type Journal Article
  Year 2013 Publication Frontiers in Zoology Abbreviated Journal Front Zool  
  Volume 10 Issue 1 Pages 60  
  Keywords European blackbirds; birds; Turdus merula; animals; melatonin; *Photoperiod  
  Abstract INTRODUCTION: Artificial light-at-night is known to affect a broad array of behaviours and physiological processes. In urbanized bird species, light-at-night advances important biological rhythms such as daily cycles of activity/rest and timing of reproduction, but our knowledge of the underlying physiological mechanisms is limited. Given its role as chronobiological signal, melatonin is a strong candidate for mediating the effects of light-at-night. RESULTS: We exposed urban and rural European blackbirds (Turdus merula) to two light treatments equal in photoperiod but with different light intensities at night. The control group was exposed to 0.0001 lux (almost darkness), while the experimental group was exposed to 0.3 lux at night, simulating conditions recorded previously on free-living urban blackbirds. We obtained diel profiles of plasma melatonin for all birds in summer (July) and winter (January), while simultaneously recording locomotor activity. Daily patterns of melatonin concentrations were clearly affected by light-at-night in both seasons. In winter, melatonin concentrations of light-at-night birds were lower in the early and late night than in those of birds kept in darkness. In summer, melatonin concentrations of the light-at-night birds were lower through all night compared to birds kept in darkness. Locomotor activity in light-at-night birds was overall higher than in control individuals, both during the day and at night, and it increased sharply before dawn. In winter, the amount of activity before dawn in the light-at-night group correlated with changes in melatonin from midnight to late night: the greater the decrease in melatonin, the greater the amount of pre-dawn activity. Urban and rural birds responded similarly to light-at-night with respect to melatonin, but differed in their behaviour, with rural birds showing more locomotor activity than urban counterparts. CONCLUSIONS: This study points to reduced melatonin release at night as a potential physiological mechanism underlying the advanced onset of morning activity of urbanized birds. Based on the pattern of melatonin secretion, we suggest that birds responded to light-at-night as if they were exposed to a longer day than birds kept under dark nights.  
  Address Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell, Germany. ddominoni@orn.mpg.de  
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  Series Volume Series Issue Edition  
  ISSN 1742-9994 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:24090446; PMCID:PMC3850952 Approved no  
  Call Number IDA @ john @ Serial 41  
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Author (down) Craggs, J.; Guest, J.R.; Davis, M.; Simmons, J.; Dashti, E.; Sweet, M. url  doi
openurl 
  Title Inducing broadcast coral spawning ex situ: Closed system mesocosm design and husbandry protocol Type Journal Article
  Year 2017 Publication Ecology and Evolution Abbreviated Journal Ecol Evol  
  Volume 7 Issue 24 Pages 11066-11078  
  Keywords Moonlight; Animals; *Acropora; *gametogenic cycle ex situ; *insolation; *lunar cycle; *photoperiod  
  Abstract For many corals, the timing of broadcast spawning correlates strongly with a number of environmental signals (seasonal temperature, lunar, and diel cycles). Robust experimental studies examining the role of these putative cues in triggering spawning have been lacking until recently because it has not been possible to predictably induce spawning in fully closed artificial mesocosms. Here, we present a closed system mesocosm aquarium design that utilizes microprocessor technology to accurately replicate environmental conditions, including photoperiod, seasonal insolation, lunar cycles, and seasonal temperature from Singapore and the Great Barrier Reef (GBR), Australia. Coupled with appropriate coral husbandry, these mesocosms were successful in inducing, for the first time, broadcast coral spawning in a fully closed artificial ex situ environment. Four Acropora species (A. hyacinthus, A. tenuis, A. millepora, and A. microclados) from two geographical locations, kept for over 1 year, completed full gametogenic cycles ex situ. The percentage of colonies developing oocytes varied from ~29% for A. hyacinthus to 100% for A. millepora and A. microclados. Within the Singapore mesocosm, A. hyacinthus exhibited the closest synchronization to wild spawning, with all four gravid colonies releasing gametes in the same lunar month as wild predicted dates. Spawning within the GBR mesocosm commenced at the predicted wild spawn date but extended over a period of 3 months. Gamete release in relation to the time postsunset for A. hyacinthus, A. millepora, and A. tenuis was consistent with time windows previously described in the wild. Spawn date in relation to full moon, however, was delayed in all species, possibly as a result of external light pollution. The system described here could broaden the number of institutions on a global scale, that can access material for broadcast coral spawning research, providing opportunities for institutions distant from coral reefs to produce large numbers of coral larvae and juveniles for research purposes and reef restoration efforts.  
  Address Aquatic Research Facility Environmental Sustainability Research Centre College of Life and Natural Sciences University of Derby Derby UK  
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  Series Volume Series Issue Edition  
  ISSN 2045-7758 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:29299282; PMCID:PMC5743687 Approved no  
  Call Number GFZ @ kyba @ Serial 2698  
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