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Author Topping, M.G.; Millar, J.S.; Goddard, J.A.
Title The effects of moonlight on nocturnal activity in bushy-tailed wood rats (Neotoma cinerea) Type Journal Article
Year 1999 Publication Canadian Journal of Zoology Abbreviated Journal Can. J. Zool.
Volume 77 Issue 3 Pages 480-485
Keywords animals; mammals; rats; bushy-tailed wood rat; Neotoma cinerea; Canada; foraging; reproduction; moonlight; predation risk
Abstract The nocturnal activity of bushy-tailed wood rats (Neotoma cinerea) was monitored for two breeding seasons (1993 and 1994) in the Canadian Rockies. Radiotelemetry was used under three levels of moonlight to assess two measures of nocturnal activity: (i) the proportion of animals crossing rocky outcrops and entering the surrounding forest to forage, search for mates, or both, and (ii) the distance moved from the den site while in the forest. Males and females exhibited significant differences among moonlight levels, with greater activity on nights of intermediate-level moonlight and less activity on nights with bright or dark moonlight. There was no difference in the proportions of males and females active at any moonlight level. The distances moved from the den did not differ among moonlight levels for either males or females. Having traversed the rocks and entered the forest, individuals moved similar distances regardless of light level. These results suggest that wood rats respond to moonlight only when making the decision to cross rocks and enter the forest. This behaviour presumably serves to counteract the increased risk of predation on bright nights.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-4301 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 88
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Author Bukalev, A.V.; Vinogradova, I.A.; Zabezhinskii, M.A.; Semenchenko, A.V.; Anisimov, V.N.
Title Light pollution increases morbidity and mortality rate from different causes in female rats Type Journal Article
Year 2013 Publication Advances in Gerontology Abbreviated Journal Adv Gerontol
Volume 3 Issue 3 Pages 180-188
Keywords light-at-night; spontaneous tumors; nontumor pathology epiphysis; rats; animals; mammals
Abstract The influence of different light regimes (constant light, LL; constant darkness, DD; standard light regime, LD, 12 hours light/12 hours darkness; and natural lighting of the northwest of Russia (NL) on non-tumor pathology revealed in the post-mortem examination of female rats has been studied. It was found that keeping 25-days-old animals under LL and NL conditions led to an increase in the number of infectious diseases and the substantially faster development of spontaneous tumors (2.9 and 3.3 diseases per one rat, respectively), variety of nontumor pathology found in dead rats, compared with the animals in standard (standard light) regime (1.72 diseases per one rat). Light deprivation (DD) led to a substantial reduction in the development of new growth, as well as nontumor and infectious diseases (1.06 diseases per one rat), compared to the same parameters in a standard light regime.
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Publisher Place of Publication (up) Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2079-0570 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 89
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Author Bedrosian, T.A.; Fonken, L.K.; Walton, J.C.; Nelson, R.J.
Title Chronic exposure to dim light at night suppresses immune responses in Siberian hamsters Type Journal Article
Year 2011 Publication Biology Letters Abbreviated Journal Biol Lett
Volume 7 Issue 3 Pages 468-471
Keywords Animals; Blood Bactericidal Activity/immunology; Circadian Rhythm; Cricetinae; Fever/immunology; Hypersensitivity, Delayed/immunology; *Immunity; Light/*adverse effects; Lipopolysaccharides; Locomotion; Phodopus/*immunology
Abstract Species have been adapted to specific niches optimizing survival and reproduction; however, urbanization by humans has dramatically altered natural habitats. Artificial light at night (LAN), termed 'light pollution', is an often overlooked, yet increasing disruptor of habitats, which perturbs physiological processes that rely on precise light information. For example, LAN alters the timing of reproduction and activity in some species, which decreases the odds of successful breeding and increases the threat of predation for these individuals, leading to reduced fitness. LAN also suppresses immune function, an important proxy for survival. To investigate the impact of LAN in a species naive to light pollution in its native habitat, immune function was examined in Siberian hamsters derived from wild-caught stock. After four weeks exposure to dim LAN, immune responses to three different challenges were assessed: (i) delayed-type hypersensitivity (DTH), (ii) lipopolysaccharide-induced fever, and (iii) bactericide activity of blood. LAN suppressed DTH response and reduced bactericide activity of blood after lipopolysaccharide treatment, in addition to altering daily patterns of locomotor activity, suggesting that human encroachment on habitats via night-time lighting may inadvertently compromise immune function and ultimately fitness.
Address Department of Neuroscience, The Ohio State University Medical Center, Columbus, OH 43210, USA. tracy.bedrosian@osumc.edu
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Publisher Place of Publication (up) Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1744-9561 ISBN Medium
Area Expedition Conference
Notes PMID:21270021; PMCID:PMC3097873 Approved no
Call Number IDA @ john @ Serial 90
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Author Fonken, L.K.; Kitsmiller, E.; Smale, L.; Nelson, R.J.
Title Dim nighttime light impairs cognition and provokes depressive-like responses in a diurnal rodent Type Journal Article
Year 2012 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume 27 Issue 4 Pages 319-327
Keywords Analysis of Variance; Animals; CA1 Region, Hippocampal/cytology; CA3 Region, Hippocampal/cytology; Circadian Rhythm/*physiology; Cognition/*physiology/radiation effects; Corticosterone/blood; Dendrites/physiology/radiation effects; Dentate Gyrus/cytology; Depressive Disorder/*physiopathology; Food Preferences/physiology/radiation effects; Light; Male; Maze Learning/physiology/radiation effects; Motor Activity/physiology/radiation effects; Murinae/*physiology; Neurons/drug effects/physiology; *Photoperiod; Swimming/physiology
Abstract Circadian disruption is a common by-product of modern life. Although jet lag and shift work are well-documented challenges to circadian organization, many more subtle environmental changes cause circadian disruption. For example, frequent fluctuations in the timing of the sleep/wake schedule, as well as exposure to nighttime lighting, likely affect the circadian system. Most studies of these effects have focused on nocturnal rodents, which are very different from diurnal species with respect to their patterns of light exposure and the effects that light can have on their activity. Thus, the authors investigated the effect of nighttime light on behavior and the brain of a diurnal rodent, the Nile grass rat. Following 3 weeks of exposure to standard light/dark (LD; 14:10 light [~150 lux] /dark [0 lux]) or dim light at night (dLAN; 14:10 light [~150 lux] /dim [5 lux]), rats underwent behavioral testing, and hippocampal neurons within CA1, CA3, and the dentate gyrus (DG) were examined. Three behavioral effects of dLAN were observed: (1) decreased preference for a sucrose solution, (2) increased latency to float in a forced swim test, and (3) impaired learning and memory in the Barnes maze. Light at night also reduced dendritic length in DG and basilar CA1 dendrites. Dendritic length in the DG positively correlated with sucrose consumption in the sucrose anhedonia task. Nighttime light exposure did not disrupt the pattern of circadian locomotor activity, and all grass rats maintained a diurnal activity pattern. Together, these data suggest that exposure to dLAN can alter affective responses and impair cognition in a diurnal animal.
Address Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA. fonken.1@osu.edu
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0748-7304 ISBN Medium
Area Expedition Conference
Notes PMID:22855576 Approved no
Call Number IDA @ john @ Serial 91
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Author Summa, K.C.; Vitaterna, M.H.; Turek, F.W.
Title Environmental perturbation of the circadian clock disrupts pregnancy in the mouse Type Journal Article
Year 2012 Publication PloS one Abbreviated Journal PLoS One
Volume 7 Issue 5 Pages e37668
Keywords Animals; Circadian Rhythm/*physiology; *Environment; Female; Locomotion/physiology; Mice; Mice, Inbred C57BL; Photoperiod; Pregnancy; Pregnancy Outcome; Reproduction/*physiology
Abstract BACKGROUND: The circadian clock has been linked to reproduction at many levels in mammals. Epidemiological studies of female shift workers have reported increased rates of reproductive abnormalities and adverse pregnancy outcomes, although whether the cause is circadian disruption or another factor associated with shift work is unknown. Here we test whether environmental disruption of circadian rhythms, using repeated shifts of the light:dark (LD) cycle, adversely affects reproductive success in mice. METHODOLOGY/PRINCIPAL FINDINGS: Young adult female C57BL/6J (B6) mice were paired with B6 males until copulation was verified by visual identification of vaginal plug formation. Females were then randomly assigned to one of three groups: control, phase-delay or phase-advance. Controls remained on a constant 12-hr light:12-hr dark cycle, whereas phase-delayed and phase-advanced mice were subjected to 6-hr delays or advances in the LD cycle every 5-6 days, respectively. The number of copulations resulting in term pregnancies was determined. Control females had a full-term pregnancy success rate of 90% (11/12), which fell to 50% (9/18; p<0.1) in the phase-delay group and 22% (4/18; p<0.01) in the phase-advance group. CONCLUSIONS/SIGNIFICANCE: Repeated shifting of the LD cycle, which disrupts endogenous circadian timekeeping, dramatically reduces pregnancy success in mice. Advances of the LD cycle have a greater negative impact on pregnancy outcomes and, in non-pregnant female mice, require longer for circadian re-entrainment, suggesting that the magnitude or duration of circadian misalignment may be related to the severity of the adverse impact on pregnancy. These results explicitly link disruptions of circadian entrainment to adverse pregnancy outcomes in mammals, which may have important implications for the reproductive health of female shift workers, women with circadian rhythm sleep disorders and/or women with disturbed circadian rhythms for other reasons.
Address Center for Sleep and Circadian Biology, Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
Corporate Author Thesis
Publisher Place of Publication (up) Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:22649550; PMCID:PMC3359308 Approved no
Call Number IDA @ john @ Serial 92
Permanent link to this record