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Author Fonken, L.K.; Workman, J.L.; Walton, J.C.; Weil, Z.M.; Morris, J.S.; Haim, A.; Nelson, R.J.
Title Light at night increases body mass by shifting the time of food intake Type Journal Article
Year 2010 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal Proc Natl Acad Sci U S A
Volume 107 Issue 43 Pages 18664-18669
Keywords Animals; Body Mass Index; *Circadian Rhythm; Disease Models, Animal; Eating/*physiology/psychology/*radiation effects; Energy Intake; Feeding Behavior/physiology/psychology/radiation effects; Glucose Tolerance Test; Humans; Male; Metabolic Syndrome X/etiology; Mice; Motor Activity; Obesity/*etiology/pathology/physiopathology/psychology; *Photoperiod
Abstract The global increase in the prevalence of obesity and metabolic disorders coincides with the increase of exposure to light at night (LAN) and shift work. Circadian regulation of energy homeostasis is controlled by an endogenous biological clock that is synchronized by light information. To promote optimal adaptive functioning, the circadian clock prepares individuals for predictable events such as food availability and sleep, and disruption of clock function causes circadian and metabolic disturbances. To determine whether a causal relationship exists between nighttime light exposure and obesity, we examined the effects of LAN on body mass in male mice. Mice housed in either bright (LL) or dim (DM) LAN have significantly increased body mass and reduced glucose tolerance compared with mice in a standard (LD) light/dark cycle, despite equivalent levels of caloric intake and total daily activity output. Furthermore, the timing of food consumption by DM and LL mice differs from that in LD mice. Nocturnal rodents typically eat substantially more food at night; however, DM mice consume 55.5% of their food during the light phase, as compared with 36.5% in LD mice. Restricting food consumption to the active phase in DM mice prevents body mass gain. These results suggest that low levels of light at night disrupt the timing of food intake and other metabolic signals, leading to excess weight gain. These data are relevant to the coincidence between increasing use of light at night and obesity in humans.
Address Department of Neuroscience, 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
ISSN 0027-8424 ISBN Medium
Area Expedition Conference
Notes (up) PMID:20937863; PMCID:PMC2972983 Approved no
Call Number IDA @ john @ Serial 169
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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
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 1744-9561 ISBN Medium
Area Expedition Conference
Notes (up) PMID:21270021; PMCID:PMC3097873 Approved no
Call Number IDA @ john @ Serial 90
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Author Sherman, H.; Gutman, R.; Chapnik, N.; Meylan, J.; le Coutre, J.; Froy, O.
Title Caffeine alters circadian rhythms and expression of disease and metabolic markers Type Journal Article
Year 2011 Publication The International Journal of Biochemistry & Cell Biology Abbreviated Journal Int J Biochem Cell Biol
Volume 43 Issue 5 Pages 829-838
Keywords Human Health; Animals; Biological Markers/blood/metabolism; Body Weight/drug effects/physiology; Caffeine/*pharmacology; Caloric Restriction; Circadian Rhythm/*drug effects/genetics/physiology; *Disease/genetics; Eating/drug effects/physiology; Gene Expression Regulation/*drug effects/genetics; HEK293 Cells; Humans; Inflammation/metabolism; Male; Mice; Mice, Inbred C57BL; Motor Activity/drug effects/physiology
Abstract The circadian clock regulates many aspects of physiology, energy metabolism, and sleep. Restricted feeding (RF), a regimen that restricts the duration of food availability entrains the circadian clock. Caffeine has been shown to affect both metabolism and sleep. However, its effect on clock gene and clock-controlled gene expression has not been studied. Here, we tested the effect of caffeine on circadian rhythms and the expression of disease and metabolic markers in the serum, liver, and jejunum of mice supplemented with caffeine under ad libitum (AL) feeding or RF for 16 weeks. Caffeine significantly affected circadian oscillation and the daily levels of disease and metabolic markers. Under AL, caffeine reduced the average daily mRNA levels of certain disease and inflammatory markers, such as liver alpha fetoprotein (Afp), C-reactive protein (Crp), jejunum alanine aminotransferase (Alt), growth arrest and DNA damage 45beta (Gadd45beta), Interleukin 1alpha (Il-1alpha), Il-1beta mRNA and serum plasminogen activator inhibitor 1 (PAI-1). Under RF, caffeine reduced the average daily levels of Alt, Gadd45beta, Il-1alpha and Il-1beta mRNA in the jejunum, but not in the liver. In addition, caffeine supplementation led to decreased expression of catabolic factors under RF. In conclusion, caffeine affects circadian gene expression and metabolism possibly leading to beneficial effects mainly under AL feeding.
Address Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1357-2725 ISBN Medium
Area Expedition Conference
Notes (up) PMID:21352949 Approved no
Call Number LoNNe @ kagoburian @ Serial 810
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Author Evans, J.A.; Carter, S.N.; Freeman, D.A.; Gorman, M.R.
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
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 0306-4522 ISBN Medium
Area Expedition Conference
Notes (up) PMID:22155265; PMCID:PMC3578228 Approved no
Call Number IDA @ john @ Serial 87
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Author Sinam, B.; Sharma, S.; Thakurdas, P.; Joshi, D.S.
Title Bright photophase accelerates re-entrainment after experimental jetlag in Drosophila Type Journal Article
Year 2012 Publication Die Naturwissenschaften Abbreviated Journal Naturwissenschaften
Volume 99 Issue 7 Pages 575-578
Keywords Animals; Circadian Rhythm/*physiology; Drosophila/*physiology/*radiation effects; *Light; Motor Activity/physiology; *Photoperiod
Abstract The efficacy of bright photophase (BP) in accelerating the re-entrainment of Drosophila biarmipes rhythm following 8 h phase advance and delay of light-dark (LD) cycle was examined by subjecting the flies to 24 h LD cycles with dim photophase (DP) at 30 lx and BP at 300 lx. Re-entrainment was analysed by using the activity onset, activity offset and the duration of activity. Following LD advance or delay, the BP flies re-entrained faster than the DP flies which was attributed to the enhanced zeitgeber strength of BP. Nevertheless, the re-entrainment was a protracted process even in the BP flies since the activity offsets underwent more transients than the activity onsets. Thus, this study demonstrates that the BP accelerates the re-entrainment in D. biarmipes. It, however, also reveals that the re-entrainment is a prolonged process when the activity onset and offset are regarded as the rhythm markers.
Address Center for Biological Rhythm Research, Ahmednagar College, Ahmednagar, 414001, MS, India
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 0028-1042 ISBN Medium
Area Expedition Conference
Notes (up) PMID:22684252 Approved no
Call Number IDA @ john @ Serial 109
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