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Author Bedrosian, T.A.; Vaughn, C.A.; Galan, A.; Daye, G.; Weil, Z.M.; Nelson, R.J.
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 (down) 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 Blask, D.E.; Brainard, G.C.; Dauchy, R.T.; Hanifin, J.P.; Davidson, L.K.; Krause, J.A.; Sauer, L.A.; Rivera-Bermudez, M.A.; Dubocovich, M.L.; Jasser, S.A.; Lynch, D.T.; Rollag, M.D.; Zalatan, F.
Title Melatonin-depleted blood from premenopausal women exposed to light at night stimulates growth of human breast cancer xenografts in nude rats Type Journal Article
Year 2005 Publication Cancer Research Abbreviated Journal Cancer Res
Volume 65 Issue 23 Pages (down) 11174-11184
Keywords Human Health; Animals; Breast Neoplasms/*blood/genetics/pathology; Cell Growth Processes/physiology; Circadian Rhythm/*physiology; Female; Humans; Light; Liver Neoplasms, Experimental/metabolism; Male; Melatonin/blood/*deficiency; Premenopause/blood; RNA, Messenger/biosynthesis/genetics; Rats; Rats, Nude; Receptors, Melatonin/biosynthesis/genetics; Transplantation, Heterologous
Abstract The increased breast cancer risk in female night shift workers has been postulated to result from the suppression of pineal melatonin production by exposure to light at night. Exposure of rats bearing rat hepatomas or human breast cancer xenografts to increasing intensities of white fluorescent light during each 12-hour dark phase (0-345 microW/cm2) resulted in a dose-dependent suppression of nocturnal melatonin blood levels and a stimulation of tumor growth and linoleic acid uptake/metabolism to the mitogenic molecule 13-hydroxyoctadecadienoic acid. Venous blood samples were collected from healthy, premenopausal female volunteers during either the daytime, nighttime, or nighttime following 90 minutes of ocular bright, white fluorescent light exposure at 580 microW/cm2 (i.e., 2,800 lx). Compared with tumors perfused with daytime-collected melatonin-deficient blood, human breast cancer xenografts and rat hepatomas perfused in situ, with nocturnal, physiologically melatonin-rich blood collected during the night, exhibited markedly suppressed proliferative activity and linoleic acid uptake/metabolism. Tumors perfused with melatonin-deficient blood collected following ocular exposure to light at night exhibited the daytime pattern of high tumor proliferative activity. These results are the first to show that the tumor growth response to exposure to light during darkness is intensity dependent and that the human nocturnal, circadian melatonin signal not only inhibits human breast cancer growth but that this effect is extinguished by short-term ocular exposure to bright, white light at night. These mechanistic studies are the first to provide a rational biological explanation for the increased breast cancer risk in female night shift workers.
Address Laboratory of Chrono-Neuroendocrine Oncology, Bassett Research Institute, The Mary Imogene Bassett Hospital, Cooperstown, New York 13326, USA. david.blask@bassett.org
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 0008-5472 ISBN Medium
Area Expedition Conference
Notes PMID:16322268 Approved no
Call Number LoNNe @ kagoburian @ Serial 721
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Author Revell, V.L.; Molina, T.A.; Eastman, C.I.
Title Human phase response curve to intermittent blue light using a commercially available device Type Journal Article
Year 2012 Publication The Journal of Physiology Abbreviated Journal J Physiol
Volume 590 Issue Pt 19 Pages (down) 4859-4868
Keywords Adolescent; Adult; Circadian Clocks/physiology/*radiation effects; Female; Humans; *Light; Male; Melatonin/analysis/physiology; Saliva/chemistry; Young Adult; blue light
Abstract Light shifts the timing of the circadian clock according to a phase response curve (PRC). To date, all human light PRCs have been to long durations of bright white light. However, melanopsin, the primary photopigment for the circadian system, is most sensitive to short wavelength blue light. Therefore, to optimise light treatment it is important to generate a blue light PRC.We used a small, commercially available blue LED light box, screen size 11.2 x 6.6 cm at approximately 50 cm, approximately 200 muW cm(-2), approximately 185 lux. Subjects participated in two 5 day laboratory sessions 1 week apart. Each session consisted of circadian phase assessments to obtain melatonin profiles before and after 3 days of free-running through an ultradian light-dark cycle (2.5 h wake in dim light, 1.5 h sleep in the dark), forced desynchrony protocol. During one session subjects received intermittent blue light (three 30 min pulses over 2 h) once a day for the 3 days of free-running, and in the other session (control) they remained in dim room light, counterbalanced. The time of blue light was varied among subjects to cover the entire 24 h day. For each individual, the phase shift to blue light was corrected for the free-run determined during the control session. The blue light PRC had a broad advance region starting in the morning and extending through the afternoon. The delay region started a few hours before bedtime and extended through the night. This is the first PRC to be constructed to blue light and to a stimulus that could be used in the real world.
Address University of Surrey, Guildford, Surrey GU2 7XH, UK
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 0022-3751 ISBN Medium
Area Expedition Conference
Notes PMID:22753544; PMCID:PMC3487041 Approved no
Call Number IDA @ john @ Serial 345
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Author Lockley, S.W.; Brainard, G.C.; Czeisler, C.A.
Title High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light Type Journal Article
Year 2003 Publication The Journal of Clinical Endocrinology and Metabolism Abbreviated Journal J Clin Endocrinol Metab
Volume 88 Issue 9 Pages (down) 4502-4505
Keywords Human Health; Adult; Area Under Curve; Circadian Rhythm/*radiation effects; Female; Humans; *Light; Male; Melatonin/*metabolism; Pineal Gland/metabolism/radiation effects; Saliva/metabolism; Non-programmatic
Abstract The endogenous circadian oscillator in mammals, situated in the suprachiasmatic nuclei, receives environmental photic input from specialized subsets of photoreceptive retinal ganglion cells. The human circadian pacemaker is exquisitely sensitive to ocular light exposure, even in some people who are otherwise totally blind. The magnitude of the resetting response to white light depends on the timing, intensity, duration, number and pattern of exposures. We report here that the circadian resetting response in humans, as measured by the pineal melatonin rhythm, is also wavelength dependent. Exposure to 6.5 h of monochromatic light at 460 nm induces a two-fold greater circadian phase delay than 6.5 h of 555 nm monochromatic light of equal photon density. Similarly, 460 nm monochromatic light causes twice the amount of melatonin suppression compared to 555 nm monochromatic light, and is dependent on the duration of exposure in addition to wavelength. These studies demonstrate that the peak of sensitivity of the human circadian pacemaker to light is blue-shifted relative to the three-cone visual photopic system, the sensitivity of which peaks at approximately 555 nm. Thus photopic lux, the standard unit of illuminance, is inappropriate when quantifying the photic drive required to reset the human circadian pacemaker.
Address Division of Sleep Medicine, Brigham and Women's Hospital, and Harvard Medical School, Boston, Massachusetts 02115, USA
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 0021-972X ISBN Medium
Area Expedition Conference
Notes PMID:12970330 Approved no
Call Number LoNNe @ kagoburian @ Serial 778
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Author Kayumov, L.; Casper, R.F.; Hawa, R.J.; Perelman, B.; Chung, S.A.; Sokalsky, S.; Shapiro, C.M.
Title Blocking low-wavelength light prevents nocturnal melatonin suppression with no adverse effect on performance during simulated shift work Type Journal Article
Year 2005 Publication The Journal of Clinical Endocrinology and Metabolism Abbreviated Journal J Clin Endocrinol Metab
Volume 90 Issue 5 Pages (down) 2755-2761
Keywords Lighting; Adult; *Circadian Rhythm; Female; Humans; *Light; Male; Melatonin/*secretion; *Work Schedule Tolerance
Abstract Decreases in melatonin production in human and animals are known to be caused by environmental lighting, especially short-wavelength lighting (between 470 and 525 nm). We investigated the novel hypothesis that the use of goggles with selective exclusion of all wavelengths less than 530 nm could prevent the suppression of melatonin in bright-light conditions during a simulated shift-work experiment. Salivary melatonin levels were measured under dim (<5 lux), bright (800 lux), and filtered (800 lux) light at hourly intervals between 2000 and 0800 h in 11 healthy young males and eight females (mean age, 24.7 +/- 4.6 yr). The measurements were performed during three nonconsecutive nights over a 2-wk period. Subjective sleepiness was measured by self-report scales, whereas objective performance was assessed with the Continuous Performance Test. All subjects demonstrated preserved melatonin levels in filtered light similar to their dim-light secretion profile. Unfiltered bright light drastically suppressed melatonin production. Normalization of endogenous melatonin production while wearing goggles did not impair measures of performance, subjective sleepiness, or alertness.
Address Sleep Research Laboratory, Department of Psychiatry, University Health Network, ECW 3D-035, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8. lkayumov@uhnres.utoronto.ca
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 0021-972X ISBN Medium
Area Expedition Conference
Notes PMID:15713707 Approved no
Call Number LoNNe @ kagoburian @ Serial 640
Permanent link to this record