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Author Bedrosian, T.A.; Fonken, L.K.; Walton, J.C.; Nelson, R.J. url  doi
openurl 
  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 PMID:21270021; PMCID:PMC3097873 Approved no  
  Call Number IDA @ john @ Serial 90  
Permanent link to this record
 

 
Author Bedrosian, T.A.; Vaughn, C.A.; Galan, A.; Daye, G.; Weil, Z.M.; Nelson, R.J. url  doi
openurl 
  Title Nocturnal light exposure impairs affective responses in a wavelength-dependent manner Type Journal Article
  Year 2013 Publication The Journal of Neuroscience : the Official Journal of the Society for Neuroscience Abbreviated Journal J Neurosci  
  Volume 33 Issue 32 Pages 13081-13087  
  Keywords Analysis of Variance; Animals; Circadian Rhythm/*physiology; Cricetinae; Dose-Response Relationship, Radiation; Female; Food Deprivation/physiology; Food Preferences/physiology/radiation effects; Fourier Analysis; Gene Expression Regulation/radiation effects; Hippocampus/pathology/radiation effects; Immobility Response, Tonic/radiation effects; Light/*adverse effects; Mood Disorders/*etiology/pathology; Motor Activity/physiology/radiation effects; Phodopus; Proto-Oncogene Proteins c-fos/metabolism; Social Behavior; Suprachiasmatic Nucleus/metabolism; Time Factors  
  Abstract Life on earth is entrained to a 24 h solar cycle that synchronizes circadian rhythms in physiology and behavior; light is the most potent entraining cue. In mammals, light is detected by (1) rods and cones, which mediate visual function, and (2) intrinsically photosensitive retinal ganglion cells (ipRGCs), which primarily project to the suprachiasmatic nucleus (SCN) in the hypothalamus to regulate circadian rhythms. Recent evidence, however, demonstrates that ipRGCs also project to limbic brain regions, suggesting that, through this pathway, light may have a role in cognition and mood. Therefore, it follows that unnatural exposure to light may have negative consequences for mood or behavior. Modern environmental lighting conditions have led to excessive exposure to light at night (LAN), and particularly to blue wavelength lights. We hypothesized that nocturnal light exposure (i.e., dim LAN) would induce depressive responses and alter neuronal structure in hamsters (Phodopus sungorus). If this effect is mediated by ipRGCs, which have reduced sensitivity to red wavelength light, then we predicted that red LAN would have limited effects on brain and behavior compared with shorter wavelengths. Additionally, red LAN would not induce c-Fos activation in the SCN. Our results demonstrate that exposure to LAN influences behavior and neuronal plasticity and that this effect is likely mediated by ipRGCs. Modern sources of LAN that contain blue wavelengths may be particularly disruptive to the circadian system, potentially contributing to altered mood regulation.  
  Address Department of Neuroscience, Ohio State University Wexner Medical Center, Columbus, Ohio 43210, USA. Bedrosian.2@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 0270-6474 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:23926261 Approved no  
  Call Number IDA @ john @ Serial 27  
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Author Fonken, L.K.; Nelson, R.J. url  doi
openurl 
  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  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0166-4328 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:23291153 Approved no  
  Call Number IDA @ john @ Serial 95  
Permanent link to this record
 

 
Author Fonken, L.K.; Finy, M.S.; Walton, J.C.; Weil, Z.M.; Workman, J.L.; Ross, J.; Nelson, R.J. url  doi
openurl 
  Title Influence of light at night on murine anxiety- and depressive-like responses Type Journal Article
  Year 2009 Publication Behavioural Brain Research Abbreviated Journal Behav Brain Res  
  Volume 205 Issue 2 Pages 349-354  
  Keywords Human Health; Animals; Anxiety/*physiopathology; Corticosterone/blood; Depression/*physiopathology; Dietary Sucrose/administration & dosage; Drinking Behavior/physiology; Light/*adverse effects; Lighting; Locomotion/physiology; Male; Maze Learning; Mice; Neuropsychological Tests; Organ Size; Photic Stimulation; *Photoperiod; Random Allocation; Swimming; Testis/pathology  
  Abstract Individuals are increasingly exposed to light at night. Exposure to constant light (LL) disrupts circadian rhythms of locomotor activity, body temperature, hormones, and the sleep-wake cycle in animals. Other behavioural responses to LL have been reported, but are inconsistent. The present experiment sought to determine whether LL produces changes in affective responses and whether behavioural changes are mediated by alterations in glucocorticoid concentrations. Relative to conspecifics maintained in a light/dark cycle (LD, 16:8 light/dark), male Swiss-Webster mice exposed to LL for three weeks increased depressive-like behavioural responses as evaluated by the forced swim test and sucrose anhedonia. Furthermore, providing a light escape tube reversed the effects of LL in the forced swim test. LL mice displayed reduced anxiety as evaluated by the open field and elevated-plus maze. Glucocorticoid concentrations were reduced in the LL group suggesting that the affective behavioural responses to LL are not the result of elevated corticosterone. Additionally, mice housed in LD with a clear tube displayed increased paired testes mass as compared to LL mice. Taken together, these data provide evidence that exposure to unnatural lighting can induce significant changes in affect, increasing depressive-like and decreasing anxiety-like responses.  
  Address Department of Psychology, The Ohio State University, Columbus, OH 43210, USA. Fonken.1@osu.edu  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0166-4328 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:19591880 Approved no  
  Call Number LoNNe @ kagoburian @ Serial 749  
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Author Hölker, F.; Wolter, C.; Perkin, E.K.; Tockner, K. url  doi
openurl 
  Title Light pollution as a biodiversity threat Type Journal Article
  Year 2010 Publication Trends in Ecology & Evolution Abbreviated Journal Trends Ecol Evol  
  Volume 25 Issue 12 Pages 681-682  
  Keywords *Biodiversity; Biological Clocks; Biological Evolution; Ecosystem; *Environmental Monitoring; *Environmental Pollutants; Light/*adverse effects  
  Abstract  
  Address  
  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 0169-5347 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:21035893 Approved no  
  Call Number IDA @ john @ Serial 36  
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