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Author Pilorz, V.; Tam, S.K.E.; Hughes, S.; Pothecary, C.A.; Jagannath, A.; Hankins, M.W.; Bannerman, D.M.; Lightman, S.L.; Vyazovskiy, V.V.; Nolan, P.M.; Foster, R.G.; Peirson, S.N.
Title Melanopsin Regulates Both Sleep-Promoting and Arousal-Promoting Responses to Light Type Journal Article
Year 2016 Publication PLoS Biology Abbreviated Journal PLoS Biol
Volume 14 Issue 6 Pages (down) e1002482
Keywords Human health; melanopsin; sleep; circadian rhythm
Abstract Light plays a critical role in the regulation of numerous aspects of physiology and behaviour, including the entrainment of circadian rhythms and the regulation of sleep. These responses involve melanopsin (OPN4)-expressing photosensitive retinal ganglion cells (pRGCs) in addition to rods and cones. Nocturnal light exposure in rodents has been shown to result in rapid sleep induction, in which melanopsin plays a key role. However, studies have also shown that light exposure can result in elevated corticosterone, a response that is not compatible with sleep. To investigate these contradictory findings and to dissect the relative contribution of pRGCs and rods/cones, we assessed the effects of light of different wavelengths on behaviourally defined sleep. Here, we show that blue light (470 nm) causes behavioural arousal, elevating corticosterone and delaying sleep onset. By contrast, green light (530 nm) produces rapid sleep induction. Compared to wildtype mice, these responses are altered in melanopsin-deficient mice (Opn4-/-), resulting in enhanced sleep in response to blue light but delayed sleep induction in response to green or white light. We go on to show that blue light evokes higher Fos induction in the SCN compared to the sleep-promoting ventrolateral preoptic area (VLPO), whereas green light produced greater responses in the VLPO. Collectively, our data demonstrates that nocturnal light exposure can have either an arousal- or sleep-promoting effect, and that these responses are melanopsin-mediated via different neural pathways with different spectral sensitivities. These findings raise important questions relating to how artificial light may alter behaviour in both the work and domestic setting.
Address Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom; stuart.peirson(at)eye.ox.ac.uk (SNP); russell.foster(at)eye.ox.ac.uk (RGF).
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:27276063; PMCID:PMC4898879 Approved no
Call Number IDA @ john @ Serial 1490
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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 5 Pages (down) 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 Walmsley, L.; Hanna, L.; Mouland, J.; Martial, F.; West, A.; Smedley, A.R.; Bechtold, D.A.; Webb, A.R.; Lucas, R.J.; Brown, T.M.
Title Colour As a Signal for Entraining the Mammalian Circadian Clock Type Journal Article
Year 2015 Publication PLoS Biology Abbreviated Journal PLoS Biol
Volume 13 Issue 4 Pages (down) e1002127
Keywords Animals; biology; color; circadian disruption; animal models; mouse models; Suprachiasmatic Nucleus; Photoperiod; twilight
Abstract Twilight is characterised by changes in both quantity (“irradiance”) and quality (“colour”) of light. Animals use the variation in irradiance to adjust their internal circadian clocks, aligning their behaviour and physiology with the solar cycle. However, it is currently unknown whether changes in colour also contribute to this entrainment process. Using environmental measurements, we show here that mammalian blue-yellow colour discrimination provides a more reliable method of tracking twilight progression than simply measuring irradiance. We next use electrophysiological recordings to demonstrate that neurons in the mouse suprachiasmatic circadian clock display the cone-dependent spectral opponency required to make use of this information. Thus, our data show that some clock neurons are highly sensitive to changes in spectral composition occurring over twilight and that this input dictates their response to changes in irradiance. Finally, using mice housed under photoperiods with simulated dawn/dusk transitions, we confirm that spectral changes occurring during twilight are required for appropriate circadian alignment under natural conditions. Together, these data reveal a new sensory mechanism for telling time of day that would be available to any mammalian species capable of chromatic vision.
Address Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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:25884537 Approved no
Call Number IDA @ john @ Serial 1152
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Author Escobar, C.; Salgado-Delgado, R.; Gonzalez-Guerra, E.; Tapia Osorio, A.; Angeles-Castellanos, M.; Buijs, R.M.
Title Circadian disruption leads to loss of homeostasis and disease Type Journal Article
Year 2011 Publication Sleep Disorders Abbreviated Journal Sleep Disord
Volume 2011 Issue Pages (down) 964510
Keywords Human Health
Abstract The relevance of a synchronized temporal order for adaptation and homeostasis is discussed in this review. We present evidence suggesting that an altered temporal order between the biological clock and external temporal signals leads to disease. Evidence mainly based on a rodent model of “night work” using forced activity during the sleep phase suggests that altered activity and feeding schedules, out of phase from the light/dark cycle, may be the main cause for the loss of circadian synchrony and disease. It is proposed that by avoiding food intake during sleep hours the circadian misalignment and adverse consequences can be prevented. This review does not attempt to present a thorough revision of the literature, but instead it aims to highlight the association between circadian disruption and disease with special emphasis on the contribution of feeding schedules in circadian synchrony.
Address Departamento de Anatomia, Facultad de Medicina, Universidad Nacional Autonoma de Mexico, 04360 Mexico City, DF, Mexico
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 2090-3553 ISBN Medium
Area Expedition Conference
Notes PMID:23471148; PMCID:PMC3581131 Approved no
Call Number LoNNe @ kagoburian @ Serial 745
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Author Ban, Y.; Cao, C.; Shao, X.
Title Assessment of scan-angle dependent radiometric bias of Suomi-NPP VIIRS day/night band from night light point source observations Type Journal Article
Year 2015 Publication Proc. SPIE 9607, Earth Observing Systems XX, 2015 Abbreviated Journal
Volume Issue Pages (down) 960727
Keywords Remote sensing; Suomi NPP; VIIRS DNB; calibration
Abstract The low gain stage of VIIRS Day/Night Band (DNB) on Suomi-NPP is calibrated using onboard solar diffuser. The calibration is then transferred to the high gain stage of DNB based on the gain ratio determined from data collected along solar terminator region. The calibration transfer causes increase of uncertainties and affects the accuracy of the low light radiances observed by DNB at night. Since there are 32 aggregation zones from nadir to the edge of the scan and each zone has its own calibration, the calibration versus scan angle of DNB needs to be independently assessed. This study presents preliminary analysis of the scan-angle dependence of the light intensity from bridge lights, oil platforms, power plants, and flares observed by VIIRS DNB since 2014. Effects of atmospheric path length associated with scan angle are analyzed. In addition, other effects such as light changes at the time of observation are also discussed. The methodology developed will be especially useful for JPSS J1 VIIRS due to the nonlinearity effects at high scan angles, and the modification of geolocation software code for different aggregation modes. It is known that J1 VIIRS DNB has large nonlinearity across aggregation zones, and requires new aggregation modes, as well as more comprehensive validation.
Address Univ. of Maryland, College Park, USA
Corporate Author Thesis
Publisher SPIE Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 1259
Permanent link to this record