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Author Wang, H.-B.; Whittaker, D.S.; Truong, D.; Mulji, A.K.; Ghiani, C.A.; Loh, D.H.; Colwell, C.S.
Title Blue light therapy improves circadian dysfunction as well as motor symptoms in two mouse models of Huntington's disease Type Journal Article
Year 2017 Publication Neurobiology of Sleep and Circadian Rhythms Abbreviated Journal Neurobiology of Sleep and Circadian Rhythms
Volume (down) 2 Issue Pages 39-52
Keywords animals; Human Health
Abstract Patients with Huntington's disease (HD) exhibit movement disorders, psychiatric disturbance and cognitive impairments as the disease progresses. Abnormal sleep/wake cycles are common among HD patients with reports of delayed sleep onset, fatigue during the day, and a delayed pattern of melatonin secretion all of which suggest circadian dysfunction. Mouse models of HD confirm disrupted circadian rhythms with pathophysiology found in the central circadian clock (suprachiasmatic nucleus). Importantly, circadian dysfunction manifests early in disease, even before the classic motor symptoms, in both patients and mouse models. Therefore, we hypothesize that the circadian dysfunction may interact with the disease pathology and exacerbate the HD symptoms. If correct, early intervention may benefit patients and delay disease progression. One test of this hypothesis is to determine whether light therapy designed to strengthen this intrinsic timing system can delay the disease progression in mouse models. Therefore, we determined the impact of blue wavelength-enriched light on two HD models: the BACHD and Q175 mice. Both models received 6 hours of blue-light at the beginning of their daily light cycle for 3 months. After treatment, both genotypes showed improvements in their locomotor activity rhythm without significant change to their sleep behavior. Critically, treated mice of both lines exhibited improved motor performance compared to untreated controls. Focusing on the Q175 genotype, we sought to determine whether the treatment altered signaling pathways in brain regions known to be impacted by HD using NanoString gene expression assays. We found that the expression of several HD relevant markers was altered in the striatum and cortex of the treated mice. Our study demonstrates that strengthening the circadian system can delay the progression of HD in pre-clinical models. This work suggests that lighting conditions should be considered when managing treatment of HD and other neurodegenerative disorders.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2451-9944 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1626
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Author Aarts, M.P.J.; Hartmeyer, S.L.; Morsink, K.; Kort, H.S.M.; de Kort, Y.A.W.
Title Can Special Light Glasses Reduce Sleepiness and Improve Sleep of Nightshift Workers? A Placebo-Controlled Explorative Field Study Type Journal Article
Year 2020 Publication Clocks & Sleep Abbreviated Journal Clocks & Sleep
Volume (down) 2 Issue 2 Pages 225-245
Keywords Human Health
Abstract Nightshift workers go against the natural sleep–wake rhythm. Light can shift the circadian clock but can also induce acute alertness. This placebo-controlled exploratory field study examined the effectiveness of light glasses to improve alertness while reducing the sleep complaints of hospital nurses working nightshifts. In a crossover within-subjects design, 23 nurses participated, using treatment glasses and placebo glasses. Sleepiness and sleep parameters were measured. A linear mixed model analysis on sleepiness revealed no significant main effect of the light intervention. An interaction effect was found indicating that under the placebo condition, sleepiness was significantly higher on the first nightshift than on the last night, while under the treatment condition, sleepiness remained stable across nightshift sessions. Sleepiness during the commute home also showed a significant interaction effect, demonstrating that after the first nightshift, driver sleepiness was higher for placebo than for treatment. Subjective sleep quality showed a negative main effect of treatment vs. placebo, particularly after the first nightshift. In retrospect, both types of light glasses were self-rated as effective. The use of light glasses during the nightshift may help to reduce driver sleepiness during the commute home, which is relevant, as all participants drove home by car or (motor) bike.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2624-5175 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2977
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Author Akacem, L.D.; Wright, K.P.J.; LeBourgeois, M.K.
Title Bedtime and evening light exposure influence circadian timing in preschool-age children: A field study Type Journal Article
Year 2016 Publication Neurobiology of Sleep and Circadian Rhythms Abbreviated Journal Neurobiol Sleep Circadian Rhythms
Volume (down) 1 Issue 2 Pages 27-31
Keywords Human Health
Abstract Light exposure and sleep timing are two factors that influence inter-individual variability in the timing of the human circadian clock. The aim of this study was to quantify the degree to which evening light exposure predicts variance in circadian timing over and above bedtime alone in preschool children. Participants were 21 children ages 4.5-5.0 years (4.7 +/- 0.2 years; 9 females). Children followed their typical sleep schedules for 4 days during which time they wore a wrist actigraph to assess sleep timing and a pendant light meter to measure minute-by-minute illuminance levels in lux. On the 5th day, children participated in an in-home dim-light melatonin onset (DLMO) assessment. Light exposure in the 2 h before bedtime was averaged and aggregated across the 4 nights preceding the DLMO assessment. Mean DLMO and bedtime were 19:22 +/- 01:04 and 20:07 +/- 00:46, respectively. Average evening light exposure was 710.1 +/- 1418.2 lux. Children with later bedtimes (lights-off time) had more delayed melatonin onset times (r=0.61, p=0.002). Evening light exposure was not independently associated with DLMO (r=0.32, p=0.08); however, a partial correlation between evening light exposure and DLMO when controlling for bedtime yielded a positive correlation (r=0.46, p=0.02). Bedtime explained 37.3% of the variance in the timing of DLMO, and evening light exposure accounted for an additional 13.3% of the variance. These findings represent an important step in understanding factors that influence circadian phase in preschool-age children and have implications for understanding a modifiable pathway that may underlie late sleep timing and the development of evening settling problems in early childhood.
Address Sleep and Development Laboratory, Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, 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 2451-9944 ISBN Medium
Area Expedition Conference
Notes PMID:28042611; PMCID:PMC5193478 Approved no
Call Number LoNNe @ kyba @ Serial 1755
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Author Lowden, A.; Lemos, N.; Gonçalves, B.; Öztürk, G.; Louzada, F.; Pedrazzoli, M.; Moreno, C.
Title Delayed Sleep in Winter Related to Natural Daylight Exposure among Arctic Day Workers Type Journal Article
Year 2018 Publication Clocks & Sleep Abbreviated Journal Clocks & Sleep
Volume (down) 1 Issue 1 Pages 105-116
Keywords Human Health
Abstract Natural daylight exposures in arctic regions vary substantially across seasons. Negative consequences have been observed in self-reports of sleep and daytime functions during the winter but have rarely been studied in detail. The focus of the present study set out to investigate sleep seasonality among indoor workers using objective and subjective measures. Sleep seasonality among daytime office workers (n = 32) in Kiruna (Sweden, 67.86° N, 20.23° E) was studied by comparing the same group of workers in a winter and summer week, including work and days off at the weekend, using actigraphs (motion loggers) and subjective ratings of alertness and mood. Actigraph analyses showed delayed sleep onset of 39 min in winter compared to the corresponding summer week (p < 0.0001) and shorter weekly sleep duration by 12 min (p = 0.0154). A delay of mid-sleep was present in winter at workdays (25 min, p < 0.0001) and more strongly delayed during days off (46 min, p < 0.0001). Sleepiness levels were higher in winter compared to summer (p < 0.05). Increased morning light exposure was associated with earlier mid-sleep (p < 0.001), while increased evening light exposure was associated with delay (p < 0.01). This study confirms earlier work that suggests that lack of natural daylight delays the sleep/wake cycle in a group of indoor workers, despite having access to electric lighting. Photic stimuli resulted in a general advanced sleep/wake rhythm during summer and increased alertness levels.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2624-5175 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2137
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Author Prayag, A.; Münch, M.; Aeschbach, D.; Chellappa, S.; Gronfier, C.
Title Light Modulation of Human Clocks, Wake, and Sleep Type Journal Article
Year 2019 Publication Clocks & Sleep Abbreviated Journal Clocks & Sleep
Volume (down) 1 Issue 1 Pages 193-208
Keywords Human Health; Review
Abstract Light, through its non-imaging forming effects, plays a dominant role on a myriad of physiological functions, including the human sleep–wake cycle. The non-image forming effects of light heavily rely on specific properties such as intensity, duration, timing, pattern, and wavelengths. Here, we address how specific properties of light influence sleep and wakefulness in humans through acute effects, e.g., on alertness, and/or effects on the circadian timing system. Of critical relevance, we discuss how different characteristics of light exposure across the 24-h day can lead to changes in sleep–wake timing, sleep propensity, sleep architecture, and sleep and wake electroencephalogram (EEG) power spectra. Ultimately, knowledge on how light affects sleep and wakefulness can improve light settings at home and at the workplace to improve health and well-being and optimize treatments of chronobiological disorders.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2624-5175 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2266
Permanent link to this record