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Author Correa, A.; Barba, A.; Padilla, F. url  doi
openurl 
  Title Light Effects on Behavioural Performance Depend on the Individual State of Vigilance Type Journal Article
  Year 2016 Publication PloS one Abbreviated Journal PLoS One  
  Volume 11 Issue 11 Pages (down) e0164945  
  Keywords Human Health  
  Abstract Research has shown that exposure to bright white light or blue-enriched light enhances alertness, but this effect is not consistently observed in tasks demanding high-level cognition (e.g., Sustained Attention to Response Task-SART, which measures inhibitory control). Individual differences in sensitivity to light effects might be mediated by variations in the basal level of arousal. We tested this hypothesis by measuring the participants' behavioural state of vigilance before light exposure, through the Psychomotor Vigilance Task. Then we compared the effects of a blue-enriched vs. dim light at nighttime on the performance of the auditory SART, by controlling for individual differences in basal arousal. The results replicated the alerting effects of blue-enriched light, as indexed by lower values of both proximal temperature and distal-proximal gradient. The main finding was that lighting effects on SART performance were highly variable across individuals and depended on their prior state of vigilance. Specifically, participants with higher levels of basal vigilance before light exposure benefited most from blue-enriched lighting, responding faster in the SART. These results highlight the importance of considering basal vigilance to define the boundary conditions of light effects on cognitive performance. Our study adds to current research delineating the complex and reciprocal interactions between lighting effects, arousal, cognitive task demands and behavioural performance.  
  Address Departamento de Psicologia Experimental. Universidad de Granada, Granada, Spain  
  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 1932-6203 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:27820822 Approved no  
  Call Number LoNNe @ kyba @ Serial 1554  
Permanent link to this record
 

 
Author Bonmati-Carrion, M.A.; Hild, K.; Isherwood, C.; Sweeney, S.J.; Revell, V.L.; Skene, D.J.; Rol, M.A.; Madrid, J.A. url  doi
openurl 
  Title Relationship between Human Pupillary Light Reflex and Circadian System Status Type Journal Article
  Year 2016 Publication PloS one Abbreviated Journal PLoS One  
  Volume 11 Issue 9 Pages (down) e0162476  
  Keywords Human Health  
  Abstract Intrinsically photosensitive retinal ganglion cells (ipRGCs), whose photopigment melanopsin has a peak of sensitivity in the short wavelength range of the spectrum, constitute a common light input pathway to the olivary pretectal nucleus (OPN), the pupillary light reflex (PLR) regulatory centre, and to the suprachiasmatic nuclei (SCN), the major pacemaker of the circadian system. Thus, evaluating PLR under short wavelength light (lambdamax </= 500 nm) and creating an integrated PLR parameter, as a possible tool to indirectly assess the status of the circadian system, becomes of interest. Nine monochromatic, photon-matched light stimuli (300 s), in 10 nm increments from lambdamax 420 to 500 nm were administered to 15 healthy young participants (8 females), analyzing: i) the PLR; ii) wrist temperature (WT) and motor activity rhythms (WA), iii) light exposure (L) pattern and iv) diurnal preference (Horne-Ostberg), sleep quality (Pittsburgh) and daytime sleepiness (Epworth). Linear correlations between the different PLR parameters and circadian status index obtained from WT, WA and L recordings and scores from questionnaires were calculated. In summary, we found markers of robust circadian rhythms, namely high stability, reduced fragmentation, high amplitude, phase advance and low internal desynchronization, were correlated with a reduced PLR to 460-490 nm wavelengths. Integrated circadian (CSI) and PLR (cp-PLR) parameters are proposed, that also showed an inverse correlation. These results demonstrate, for the first time, the existence of a close relationship between the circadian system robustness and the pupillary reflex response, two non-visual functions primarily under melanopsin-ipRGC input.  
  Address Chronobiology Laboratory, Department of Physiology, Faculty of Biology, University of Murcia, IMIB-Arrixaca, 30100, Espinardo, Murcia, Spain  
  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 1932-6203 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:27636197; PMCID:PMC5026360 Approved no  
  Call Number LoNNe @ kyba @ Serial 1537  
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Author Cheung, I.N.; Zee, P.C.; Shalman, D.; Malkani, R.G.; Kang, J.; Reid, K.J. url  doi
openurl 
  Title Morning and Evening Blue-Enriched Light Exposure Alters Metabolic Function in Normal Weight Adults Type Journal Article
  Year 2016 Publication PloS one Abbreviated Journal PLoS One  
  Volume 11 Issue 5 Pages (down) e0155601  
  Keywords Human Health  
  Abstract Increasing evidence points to associations between light-dark exposure patterns, feeding behavior, and metabolism. This study aimed to determine the acute effects of 3 hours of morning versus evening blue-enriched light exposure compared to dim light on hunger, metabolic function, and physiological arousal. Nineteen healthy adults completed this 4-day inpatient protocol under dim light conditions (<20lux). Participants were randomized to 3 hours of blue-enriched light exposure on Day 3 starting either 0.5 hours after wake (n = 9; morning group) or 10.5 hours after wake (n = 10; evening group). All participants remained in dim light on Day 2 to serve as their baseline. Subjective hunger and sleepiness scales were collected hourly. Blood was sampled at 30-minute intervals for 4 hours in association with the light exposure period for glucose, insulin, cortisol, leptin, and ghrelin. Homeostatic model assessment of insulin resistance (HOMA-IR) and area under the curve (AUC) for insulin, glucose, HOMA-IR and cortisol were calculated. Comparisons relative to baseline were done using t-tests and repeated measures ANOVAs. In both the morning and evening groups, insulin total area, HOMA-IR, and HOMA-IR AUC were increased and subjective sleepiness was reduced with blue-enriched light compared to dim light. The evening group, but not the morning group, had significantly higher glucose peak value during blue-enriched light exposure compared to dim light. There were no other significant differences between the morning or the evening groups in response to blue-enriched light exposure. Blue-enriched light exposure acutely alters glucose metabolism and sleepiness, however the mechanisms behind this relationship and its impacts on hunger and appetite regulation remain unclear. These results provide further support for a role of environmental light exposure in the regulation of metabolism.  
  Address Department of Neurology, Northwestern University, Chicago, Illinois, United States of America  
  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 1932-6203 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:27191727 Approved no  
  Call Number LoNNe @ kyba @ Serial 1457  
Permanent link to this record
 

 
Author Kozaki, T.; Hidaka, Y.; Takakura, J.-Y.; Kusano, Y. url  doi
openurl 
  Title Salivary melatonin suppression under 100-Hz flickering blue light and non-flickering blue light conditions Type Journal Article
  Year 2020 Publication Neuroscience Letters Abbreviated Journal Neurosci Lett  
  Volume 722 Issue Pages (down) 134857  
  Keywords Human Health; Flickering light; Intrinsically photosensitive retinal ganglion cell; Light; Light emitting diode; Melatonin  
  Abstract Bright light at night has been known to suppress melatonin secretion. Photoreceptors, known as intrinsically photosensitive retinal ganglion cells (ipRGCs), project dark/bright information into the superchiasmatic nucleus, which regulates the circadian system. Electroretinograms of ipRGCs show fluctuation that is synchronized with light ON-OFF stimulation. This finding suggests that the flickering condition of light may have an impact on our circadian system. In this study, we evaluate light-induced melatonin suppression under flickering and non-flickering light conditions. Fifteen male subjects between the ages of 20 and 23 years (mean +/- SD, 21.9 +/- 1.9) were exposed to three light conditions (dim, 100-Hz flickering and non-flickering light) from 1:00 a.m. to 2:30 a.m. Saliva samples were taken just before 1:00 and at 1:15, 1:30, 2:00, and 2:30 a.m. Repeated-measure t-test with Bonferroni correction showed a significant decrease in melatonin levels under both 100-Hz and non-flickering light conditions compared to dim light conditions after 2:00 a.m. Moreover, at 2:30 a.m., the rate of change in melatonin level under 100 Hz of flickering light was significantly lower than that under non-flickering light. Our present findings suggest that 100-Hz flickering light may suppress melatonin secretion more than non-flickering light.  
  Address Department of Health and Nutrition Sciences, Nishikyushu University, 4490-9 Osaki, Kanzaki, Japan  
  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 0304-3940 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:32097701 Approved no  
  Call Number GFZ @ kyba @ Serial 2855  
Permanent link to this record
 

 
Author Russart, K.L.G.; Chbeir, S.A.; Nelson, R.J.; Magalang, U.J. url  doi
openurl 
  Title Light at night exacerbates metabolic dysfunction in a polygenic mouse model of type 2 diabetes mellitus Type Journal Article
  Year 2019 Publication Life Sciences Abbreviated Journal Life Sci  
  Volume 231 Issue Pages (down) 116574  
  Keywords Animals; diabetes; human health; mouse models; Type 2 diabetes; Insulin Resistance  
  Abstract AIMS: Electric lighting is beneficial to modern society; however, it is becoming apparent that light at night (LAN) is not without biological consequences. Several studies have reported negative effects of LAN on health and behavior in humans and nonhuman animals. Exposure of non-diabetic mice to dim LAN impairs glucose tolerance, whereas a return to dark nights (LD) reverses this impairment. We predicted that exposure to LAN would exacerbate the metabolic abnormalities in TALLYHO/JngJ (TH) mice, a polygenic model of type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: We exposed 7-week old male TH mice to either LD or LAN for 8-10weeks in two separate experiments. After 8weeks of light treatment, we conducted intraperitoneal glucose tolerance testing (ipGTT) followed by intraperitoneal insulin tolerance testing (ipITT). In Experiment 1, all mice were returned to LD for 4weeks, and ipITT was repeated. KEY FINDINGS: The major results of this study are i) LAN exposure for 8weeks exacerbates glucose intolerance and insulin resistance ii) the effects of LAN on insulin resistance are reversed upon return to LD, iii) LAN exposure results in a greater increase in body weight compared to LD exposure, iv) LAN increases the incidence of mice developing overt T2DM, and v) LAN exposure decreases survival of mice with T2DM. SIGNIFICANCE: In conclusion, LAN exacerbated metabolic abnormalities in a polygenic mouse model of T2DM, and these effects were reversed upon return to dark nights. The applicability of these findings to humans with T2DM needs to be determined.  
  Address Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH 43210, 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 0024-3205 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:31207311 Approved no  
  Call Number GFZ @ kyba @ Serial 2549  
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