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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 Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition (up)
ISSN 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:22649550; PMCID:PMC3359308 Approved no
Call Number IDA @ john @ Serial 92
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Author Fonken, L.K.; Lieberman, R.A.; Weil, Z.M.; Nelson, R.J.
Title Dim light at night exaggerates weight gain and inflammation associated with a high-fat diet in male mice Type Journal Article
Year 2013 Publication Endocrinology Abbreviated Journal Endocrinology
Volume 154 Issue 10 Pages 3817-3825
Keywords Adipose Tissue, White/*immunology/metabolism/pathology; Animals; Antigens, CD11b/biosynthesis/genetics/metabolism; Appetite Regulation/*radiation effects; Arcuate Nucleus/*immunology/metabolism/pathology; Behavior, Animal/radiation effects; Circadian Rhythm; Cytokines/biosynthesis/genetics/metabolism; Diet, High-Fat/*adverse effects; Feeding Behavior/radiation effects; Gene Expression Regulation; Glucose Intolerance/etiology/immunology/metabolism/pathology; I-kappa B Kinase/biosynthesis/genetics/metabolism; Insulin Resistance; Lighting/*adverse effects; Male; Mice; Microglia/immunology/metabolism/pathology; Nerve Tissue Proteins/biosynthesis/genetics/metabolism; Obesity/*etiology/immunology/metabolism/pathology; Random Allocation; *Weight Gain
Abstract Elevated nighttime light exposure is associated with symptoms of metabolic syndrome. In industrialized societies, high-fat diet (HFD) and exposure to light at night (LAN) often cooccur and may contribute to the increasing obesity epidemic. Thus, we hypothesized that dim LAN (dLAN) would provoke additional and sustained body mass gain in mice on a HFD. Male mice were housed in either a standard light/dark cycle or dLAN and fed either chow or HFD. Exposure to dLAN and HFD increase weight gain, reduce glucose tolerance, and alter insulin secretion as compared with light/dark cycle and chow, respectively. The effects of dLAN and HFD appear additive, because mice exposed to dLAN that were fed HFD display the greatest increases in body mass. Exposure to both dLAN and HFD also change the timing of food intake and increase TNFalpha and MAC1 gene expression in white adipose tissue after 4 experimental weeks. Changes in MAC1 gene expression occur more rapidly due to HFD as compared with dLAN; after 5 days of experimental conditions, mice fed HFD already increase MAC1 gene expression in white adipose tissue. HFD also elevates microglia activation in the arcuate nucleus of the hypothalamus and hypothalamic TNFalpha, IL-6, and Ikbkb gene expression. Microglia activation is increased by dLAN, but only among chow-fed mice and dLAN does not affect inflammatory gene expression. These results suggest that dLAN exaggerates weight gain and peripheral inflammation associated with HFD.
Address Department of Neuroscience, Wexner Medical Center, The Ohio State University, 636 Biomedical Research Tower, 460 West 12th Avenue, Columbus, Ohio 43210. fonken.1@osu.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 (up)
ISSN 0013-7227 ISBN Medium
Area Expedition Conference
Notes PMID:23861373 Approved no
Call Number IDA @ john @ Serial 93
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Author Barclay, J.L.; Husse, J.; Bode, B.; Naujokat, N.; Meyer-Kovac, J.; Schmid, S.M.; Lehnert, H.; Oster, H.
Title Circadian desynchrony promotes metabolic disruption in a mouse model of shiftwork Type Journal Article
Year 2012 Publication PloS one Abbreviated Journal PLoS One
Volume 7 Issue 5 Pages e37150
Keywords Animals; Biological Clocks/*physiology; Circadian Rhythm/*physiology; Disease Models, Animal; Eating/genetics; Gene Expression Regulation; Liver/metabolism; Male; Mice; Sleep Disorders, Circadian Rhythm/*metabolism/physiopathology; Suprachiasmatic Nucleus/*metabolism; Transcriptome
Abstract Shiftwork is associated with adverse metabolic pathophysiology, and the rising incidence of shiftwork in modern societies is thought to contribute to the worldwide increase in obesity and metabolic syndrome. The underlying mechanisms are largely unknown, but may involve direct physiological effects of nocturnal light exposure, or indirect consequences of perturbed endogenous circadian clocks. This study employs a two-week paradigm in mice to model the early molecular and physiological effects of shiftwork. Two weeks of timed sleep restriction has moderate effects on diurnal activity patterns, feeding behavior, and clock gene regulation in the circadian pacemaker of the suprachiasmatic nucleus. In contrast, microarray analyses reveal global disruption of diurnal liver transcriptome rhythms, enriched for pathways involved in glucose and lipid metabolism and correlating with first indications of altered metabolism. Although altered food timing itself is not sufficient to provoke these effects, stabilizing peripheral clocks by timed food access can restore molecular rhythms and metabolic function under sleep restriction conditions. This study suggests that peripheral circadian desynchrony marks an early event in the metabolic disruption associated with chronic shiftwork. Thus, strengthening the peripheral circadian system by minimizing food intake during night shifts may counteract the adverse physiological consequences frequently observed in human shift workers.
Address Max Planck Institute of Biophysical Chemistry, Gottingen, Germany
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 (up)
ISSN 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:22629359; PMCID:PMC3357388 Approved no
Call Number IDA @ john @ Serial 94
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Author Fonken, L.K.; Nelson, R.J.
Title Dim light at night increases depressive-like responses in male C3H/HeNHsd mice Type Journal Article
Year 2013 Publication Behavioural Brain Research Abbreviated Journal Behav Brain Res
Volume 243 Issue Pages 74-78
Keywords Affect/physiology; Anhedonia/physiology; Animals; Behavior, Animal/*physiology; Circadian Rhythm/*physiology; Depression/*etiology/physiopathology; Hippocampus/*metabolism/pathology; Light/*adverse effects; Male; Mice; Mice, Inbred C3H; Neuropsychological Tests; Photoperiod
Abstract Daily patterns of light exposure have become increasingly variable since the widespread adoption of electrical lighting during the 20th century. Seasonal fluctuations in light exposure, shift-work, and transmeridian travel are all associated with alterations in mood. These studies implicate fluctuations in environmental lighting in the development of depressive disorders. Here we argue that exposure to light at night (LAN) may be causally linked to depression. Male C3H/HeNHsd mice, which produce nocturnal melatonin, were housed in either a standard light/dark (LD) cycle or exposed to nightly dim (5 lux) LAN (dLAN). After four weeks in lighting conditions mice underwent behavioral testing and hippocampal tissue was collected at the termination of the study for qPCR. Here were report that mice exposed to dLAN increase depressive-like responses in both a sucrose anhedonia and forced swim test. In contrast to findings in diurnal grass rats, dLAN mice perform comparably to mice housed under dark nights in a hippocampus-dependent learning and memory task. TNFalpha and IL1beta gene expression do not differ between groups, demonstrating that changes in these pro-inflammatory cytokines do not mediate dLAN induced depressive-like responses in mice. BDNF expression is reduced in the hippocampus of mice exposed to dLAN. These results indicate that low levels of LAN can alter mood in mice. This study along with previous work implicates LAN as a potential factor contributing to depression. Further understanding of the mechanisms through which LAN contributes to changes in mood is important for characterizing and treating depressive disorders.
Address Department of Neuroscience, Institute for Behavioral Medicine Research, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, USA. fonken.1@osu.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 (up)
ISSN 0166-4328 ISBN Medium
Area Expedition Conference
Notes PMID:23291153 Approved no
Call Number IDA @ john @ Serial 95
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Author Orbach, D.N.; Fenton, B.
Title Vision impairs the abilities of bats to avoid colliding with stationary obstacles Type Journal Article
Year 2010 Publication PloS one Abbreviated Journal PLoS One
Volume 5 Issue 11 Pages e13912
Keywords Analysis of Variance; Animals; Chiroptera/*physiology; Cyclonic Storms; Echolocation/*physiology; Female; Flight, Animal/*physiology; Light; Male; Space Perception/physiology/radiation effects; Vision, Ocular/*physiology/radiation effects; Vocalization, Animal/physiology
Abstract BACKGROUND: Free-flying insectivorous bats occasionally collide with stationary objects they should easily detect by echolocation and avoid. Collisions often occur with lighted objects, suggesting ambient light may deleteriously affect obstacle avoidance capabilities. We tested the hypothesis that free-flying bats may orient by vision when they collide with some obstacles. We additionally tested whether acoustic distractions, such as “distress calls” of other bats, contributed to probabilities of collision. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the role of visual cues in the collisions of free-flying little brown bats (Myotis lucifugus) with stationary objects, we set up obstacles in an area of high bat traffic during swarming. We used combinations of light intensities and visually dissimilar obstacles to verify that bats orient by vision. In early August, bats collided more often in the light than the dark, and probabilities of collision varied with the visibility of obstacles. However, the probabilities of collisions altered in mid to late August, coincident with the start of behavioural, hormonal, and physiological changes occurring during swarming and mating. Distress calls did not distract bats and increase the incidence of collisions. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that visual cues are more important for free-flying bats than previously recognized, suggesting integration of multi-sensory modalities during orientation. Furthermore, our study highlights differences between responses of captive and wild bats, indicating a need for more field experiments.
Address Department of Biology, University of Western Ontario, London, Ontario, Canada. dnorbach@gmail.com
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 (up)
ISSN 1932-6203 ISBN Medium
Area Expedition Conference
Notes PMID:21085481; PMCID:PMC2976695 Approved no
Call Number IDA @ john @ Serial 96
Permanent link to this record