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Author Brainard, G.C.; Sliney, D.; Hanifin, J.P.; Glickman, G.; Byrne, B.; Greeson, J.M.; Jasser, S.; Gerner, E.; Rollag, M.D.
Title Sensitivity of the human circadian system to short-wavelength (420-nm) light Type Journal Article
Year 2008 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume 23 Issue (up) 5 Pages 379-386
Keywords Human Health; Adult; Circadian Rhythm/*radiation effects; Female; Humans; *Light; Male; Melatonin/metabolism; Models, Biological; Neurosecretory Systems; Photons; Pineal Gland/metabolism; Retinal Ganglion Cells/*metabolism; Vision, Ocular
Abstract The circadian and neurobehavioral effects of light are primarily mediated by a retinal ganglion cell photoreceptor in the mammalian eye containing the photopigment melanopsin. Nine action spectrum studies using rodents, monkeys, and humans for these responses indicate peak sensitivities in the blue region of the visible spectrum ranging from 459 to 484 nm, with some disagreement in short-wavelength sensitivity of the spectrum. The aim of this work was to quantify the sensitivity of human volunteers to monochromatic 420-nm light for plasma melatonin suppression. Adult female (n=14) and male (n=12) subjects participated in 2 studies, each employing a within-subjects design. In a fluence-response study, subjects (n=8) were tested with 8 light irradiances at 420 nm ranging over a 4-log unit photon density range of 10(10) to 10(14) photons/cm(2)/sec and 1 dark exposure control night. In the other study, subjects (n=18) completed an experiment comparing melatonin suppression with equal photon doses (1.21 x 10(13) photons/cm(2)/sec) of 420 nm and 460 nm monochromatic light and a dark exposure control night. The first study demonstrated a clear fluence-response relationship between 420-nm light and melatonin suppression (p<0.001) with a half-saturation constant of 2.74 x 10(11) photons/cm(2)/sec. The second study showed that 460-nm light is significantly stronger than 420-nm light for suppressing melatonin (p<0.04). Together, the results clarify the visible short-wavelength sensitivity of the human melatonin suppression action spectrum. This basic physiological finding may be useful for optimizing lighting for therapeutic and other applications.
Address Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA. george.brainard@jefferson.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 0748-7304 ISBN Medium
Area Expedition Conference
Notes PMID:18838601 Approved no
Call Number LoNNe @ kagoburian @ Serial 724
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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 (up) 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
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 1357-2725 ISBN Medium
Area Expedition Conference
Notes PMID:21352949 Approved no
Call Number LoNNe @ kagoburian @ Serial 810
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Author van Diepen, H.C.; Foster, R.G.; Meijer, J.H.
Title A colourful clock Type Journal Article
Year 2015 Publication PLoS Biology Abbreviated Journal PLoS Biol
Volume 13 Issue (up) 5 Pages e1002160
Keywords Animals; Commentary; *Circadian Rhythm; suprachiasmatic nuclei; melanopsin; retinal ganglion cells; entrainment; photoperiod
Abstract Circadian rhythms are an essential property of life on Earth. In mammals, these rhythms are coordinated by a small set of neurons, located in the suprachiasmatic nuclei (SCN). The environmental light/dark cycle synchronizes (entrains) the SCN via a distinct pathway, originating in a subset of photosensitive retinal ganglion cells (pRGCs) that utilize the photopigment melanopsin (OPN4). The pRGCs are also innervated by rods and cones and, so, are both endogenously and exogenously light sensitive. Accumulating evidence has shown that the circadian system is sensitive to ultraviolet (UV), blue, and green wavelengths of light. However, it was unclear whether colour perception itself can help entrain the SCN. By utilizing both behavioural and electrophysiological recording techniques, Walmsley and colleagues show that multiple photic channels interact and enhance the capacity of the SCN to synchronize to the environmental cycle. Thus, entrainment of the circadian system combines both environmental irradiance and colour information to ensure that internal and external time are appropriately aligned.
Address Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University medical School, Leiden, The Netherlands
Corporate Author Thesis
Publisher PLOS Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1544-9173 ISBN Medium
Area Expedition Conference
Notes PMID:25996907; PMCID:PMC4440787 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 1183
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Author Berson, D.M.; Dunn, F.A.; Takao, M.
Title Phototransduction by retinal ganglion cells that set the circadian clock Type Journal Article
Year 2002 Publication Science (New York, N.Y.) Abbreviated Journal Science
Volume 295 Issue (up) 5557 Pages 1070-1073
Keywords Human Health; Animals; Axons/ultrastructure; *Biological Clocks; *Circadian Rhythm; Dendrites/ultrastructure; Isoquinolines; Kinetics; Light; *Light Signal Transduction; Patch-Clamp Techniques; Rats; Rats, Sprague-Dawley; Retinal Ganglion Cells/chemistry/cytology/*physiology; Rod Opsins/analysis/physiology; Suprachiasmatic Nucleus/cytology/*physiology
Abstract Light synchronizes mammalian circadian rhythms with environmental time by modulating retinal input to the circadian pacemaker-the suprachiasmatic nucleus (SCN) of the hypothalamus. Such photic entrainment requires neither rods nor cones, the only known retinal photoreceptors. Here, we show that retinal ganglion cells innervating the SCN are intrinsically photosensitive. Unlike other ganglion cells, they depolarized in response to light even when all synaptic input from rods and cones was blocked. The sensitivity, spectral tuning, and slow kinetics of this light response matched those of the photic entrainment mechanism, suggesting that these ganglion cells may be the primary photoreceptors for this system.
Address Department of Neuroscience, Brown University, Providence, RI, 02912 USA. David_Berson@brown.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 0036-8075 ISBN Medium
Area Expedition Conference
Notes PMID:11834835 Approved no
Call Number LoNNe @ kagoburian @ Serial 720
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Author Kelber, A.; Balkenius, A.; Warrant, E.J.
Title Scotopic colour vision in nocturnal hawkmoths Type Journal Article
Year 2002 Publication Nature Abbreviated Journal Nature
Volume 419 Issue (up) 6910 Pages 922-925
Keywords Animals; Behavior, Animal; Color; Color Perception/*physiology; Conditioning (Psychology)/physiology; Cues; *Darkness; Discrimination Learning/physiology; Humans; Light; Lighting; Moths/*physiology; Photic Stimulation; Photoreceptor Cells, Invertebrate/physiology; Reward; Sensitivity and Specificity; Ultraviolet Rays
Abstract Humans are colour-blind at night, and it has been assumed that this is true of all animals. But colour vision is as useful for discriminating objects at night as it is during the day. Here we show, through behavioural experiments, that the nocturnal hawkmoth Deilephila elpenor uses colour vision to discriminate coloured stimuli at intensities corresponding to dim starlight (0.0001 cd x m(-2)). It can do this even if the illumination colour changes, thereby showing colour constancy-a property of true colour vision systems. In identical conditions humans are completely colour-blind. Our calculations show that the possession of three photoreceptor classes reduces the absolute sensitivity of the eye, which indicates that colour vision has a high ecological relevance in nocturnal moths. In addition, the photoreceptors of a single ommatidium absorb too few photons for reliable discrimination, indicating that spatial and/or temporal summation must occur for colour vision to be possible. Taken together, our results show that colour vision occurs at nocturnal intensities in a biologically relevant context.
Address Department of Cell and Organism Biology, Vision Group, Lund University, Helgonavagen 3, S-22362 Lund, Sweden. almut.kelber@zool.lu.se
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 0028-0836 ISBN Medium
Area Expedition Conference
Notes PMID:12410310 Approved no
Call Number LoNNe @ kagoburian @ Serial 606
Permanent link to this record