Journal of Circadian Rhythms最新文献

{"title":"Heat the Clock: Entrainment and Compensation in <i>Arabidopsis</i> Circadian Rhythms.","authors":"Paula A Avello,&nbsp;Seth J Davis,&nbsp;James Ronald,&nbsp;Jonathan W Pitchford","doi":"10.5334/jcr.179","DOIUrl":"https://doi.org/10.5334/jcr.179","url":null,"abstract":"<p><p>The circadian clock is a biological mechanism that permits some organisms to anticipate daily environmental variations. This clock generates biological rhythms, which can be reset by environmental cues such as cycles of light or temperature, a process known as entrainment. After entrainment, circadian rhythms typically persist with approximately 24 hours periodicity in free-running conditions, <i>i.e.</i> in the absence of environmental cues. Experimental evidence also shows that a free-running period close to 24 hours is maintained across a range of temperatures, a process known as temperature compensation. In the plant <i>Arabidopsis</i>, the effect of light on the circadian system has been widely studied and successfully modelled mathematically. However, the role of temperature in periodicity, and the relationship between entrainment and compensation, are not fully understood. Here we adapt recent models to incorporate temperature dependence by applying Arrhenius equations to the parameters of the models that characterize transcription, translation, and degradation rates. We show that the resulting models can exhibit thermal entrainment and temperature compensation, but that these phenomena emerge from physiologically different sets of processes. Further simulations combining thermal and photic forcing in more realistic scenarios clearly distinguish between the processes of entrainment and compensation, and reveal temperature compensation as an emergent property which can arise as a result of multiple temperature-dependent interactions. Our results consistently point to the thermal sensitivity of degradation rates as driving compensation and entrainment across a range of conditions.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"17 ","pages":"5"},"PeriodicalIF":0.0,"publicationDate":"2019-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6524549/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37286108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Musicians: Larks, Owls or Hummingbirds?","authors":"Nikita Gjermunds,&nbsp;Inge Brechan,&nbsp;Svein Åge Kjøs Johnsen,&nbsp;Reidulf Gerhard Watten","doi":"10.5334/jcr.173","DOIUrl":"https://doi.org/10.5334/jcr.173","url":null,"abstract":"<p><p>Previous studies have shown an association between morning and evening types and creative thinking. Musicians are creative individuals and the purpose of the current research was to examine whether musicians are significantly more evening types than non-musicians. The total sample included 835 participants (n women = 353; n men = 482), with a mean age of 28.0 years (<i>SD</i> = 10.4). The group of musicians consisted of 600 participants (n women = 168; n men = 432) with a mean age of 29.1 years (<i>SD</i> = 11.2). The group of non-musicians consisted of 233 participants (n women = 184; n men = 49) with a mean age of 25.3 years (<i>SD</i> = 7.4). Participants were recruited via an online forum, and chronotypes were assessed using the self-report Horne & Ostberg's Morningness-Eveningness Questionnaire (MEQ). We found that performance musicians had significantly lower MEQ scores compared to non-performance musicians, and musicians who composed had the lowest MEQ scores across the whole sample. This indicates that musicians, particularly composing musicians had a tendency towards eveningness. These findings are discussed in relation to theories on chronobiology, creativity, and cognitive psychology.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"17 ","pages":"4"},"PeriodicalIF":0.0,"publicationDate":"2019-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6509950/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37003363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Free-Living Humans Cross Cardiovascular Disease Risk Categories Due to Daily Rhythms in Cholesterol and Triglycerides.","authors":"Azure D Grant, Gary I Wolf","doi":"10.5334/jcr.178","DOIUrl":"10.5334/jcr.178","url":null,"abstract":"<p><p>Cardiovascular disease risk assessment relies on single time-point measurement of risk factors. Although significant daily rhythmicity of some risk factors (e.g., blood pressure and blood glucose) suggests that carefully timed samples or biomarker timeseries could improve risk assessment, such rhythmicity in <i>lipid</i> risk factors is not well understood in free-living humans. As recent advances in at-home blood testing permit lipid data to be frequently and reliably self-collected during daily life, we hypothesized that total cholesterol, HDL-cholesterol or triglycerides would show significant time-of-day variability under everyday conditions. To address this hypothesis, we worked with data collected by 20 self-trackers during personal projects. The dataset consisted of 1,319 samples of total cholesterol, HDL-cholesterol and triglycerides, and comprised timeseries illustrating intra and inter-day variability. All individuals crossed at least one risk category in at least one output within a single day. 90% of fasted individuals (n = 12) crossed at least one risk category in one output during the morning hours alone (06:00-08:00) across days. Both individuals and the aggregated group show significant, rhythmic change by time of day in total cholesterol and triglycerides, but not HDL-cholesterol. Two individuals collected additional data sufficient to illustrate ultradian (hourly) fluctuation in triglycerides, and total cholesterol fluctuation across the menstrual cycle. Short-term variability of sufficient amplitude to affect diagnosis appears common. We conclude that cardiovascular risk assessment may be augmented via further research into the temporal dynamics of lipids. Some variability can be accounted for by a daily rhythm, but ultradian and menstrual rhythms likely contribute additional variance.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"17 ","pages":"3"},"PeriodicalIF":0.0,"publicationDate":"2019-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6484367/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37383727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dysregulation of Circadian Rhythm Gene Expression in Cystic Fibrosis Mice.","authors":"Eric Barbato,&nbsp;Hannah Mianzo,&nbsp;Paul Litman,&nbsp;Rebecca Darrah","doi":"10.5334/jcr.175","DOIUrl":"https://doi.org/10.5334/jcr.175","url":null,"abstract":"<p><p>Cystic fibrosis (CF) is autosomal recessive disease that affects multiple body systems. CF patients often experience sleep disturbances, altered sleep patterns, and sleep apnea. Sleep in mammals is controlled in part by circadian clock genes, including <i>Clock, Bmal1, Period1, Period2, Cryptochrome1,</i> and <i>Cryptochrome2</i>. The purpose of this study was to gain a better understanding of the biological underpinnings of disordered sleep experienced in CF. To accomplish this, we evaluated circadian clock gene expression profiles in CF and wildtype mice, divided into two subgroups each based on sleep condition. One subgroup of each genotype was permitted to maintain their sleep-wake cycle while the other was deprived of sleep for six hours prior to sacrifice. Brain, skeletal muscle, jejunum, colon, lung and adipose tissues were collected from each mouse. Quantitative polymerase chain reaction (PCR) was used to quantify expression of <i>Clock, Bmal1, Period1, Period2, Cryptochrome1</i> and <i>Cryptochrome2,</i> and expression levels were compared between study groups. Our comparisons showed distinct differences between the CF groups and the wildtype groups under both sleep conditions. Additionally, we found the CF mice that had been sleep deprived had severely dysregulated expression of all measured genes in the lung apart from <i>Cry1</i>. Our findings suggest that (1) disordered sleep in CF may be caused by circadian system dysregulation and (2) the loss of the cystic fibrosis transmembrane conductance regulator (CFTR) is a causative factor in the dysregulated circadian clock gene expression profiles of CF mice.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"17 ","pages":"2"},"PeriodicalIF":0.0,"publicationDate":"2019-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6484366/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37383726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brain Microdialysate Monoamines in Relation to Circadian Rhythms, Sleep, and Sleep Deprivation - a Systematic Review, Network Meta-analysis, and New Primary Data.","authors":"Julia M L Menon,&nbsp;Christ Nolten,&nbsp;E J Marijke Achterberg,&nbsp;Ruud N J M A Joosten,&nbsp;Maurice Dematteis,&nbsp;Matthijs G P Feenstra,&nbsp;W H Pim Drinkenburg,&nbsp;Cathalijn H C Leenaars","doi":"10.5334/jcr.174","DOIUrl":"https://doi.org/10.5334/jcr.174","url":null,"abstract":"<p><p>Disruption of the monoaminergic system, e.g. by sleep deprivation (SD), seems to promote certain diseases. Assessment of monoamine levels over the circadian cycle, during different sleep stages and during SD is instrumental to understand the molecular dynamics during and after SD. To provide a complete overview of all available evidence, we performed a systematic review. A comprehensive search was performed for microdialysis and certain monoamines (dopamine, serotonin, noradrenaline, adrenaline), certain monoamine metabolites (3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindoleacetic acid (5-HIAA)) and a precursor (5-hydroxytryptophan (5-HTP)) in PubMed and EMBASE. After screening of the search results by two independent reviewers, 94 publications were included. All results were tabulated and described qualitatively. Network-meta analyses (NMAs) were performed to compare noradrenaline and serotonin concentrations between sleep stages. We further present experimental monoamine data from the medial prefrontal cortical (mPFC). Monoamine levels varied with brain region and circadian cycle. During sleep, monoamine levels generally decreased compared to wake. These qualitative observations were supported by the NMAs: noradrenaline and serotonin levels decreased from wakefulness to slow wave sleep and decreased further during Rapid Eye Movement sleep. In contrast, monoamine levels generally increased during SD, and sometimes remained high even during subsequent recovery. Decreases during or after SD were only reported for serotonin. In our experiment, SD did not affect any of the mPFC monoamine levels. Concluding, monoamine levels vary over the light-dark cycle and between sleep stages. SD modifies the patterns, with effects sometimes lasting beyond the SD period.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"17 ","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2019-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5334/jcr.174","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36886937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overexpression of Prokineticin 2 in Transgenic Mice Leads to Reduced Circadian Behavioral Rhythmicity and Altered Molecular Rhythms in the Suprachiasmatic Clock.","authors":"Xiaohan Li,&nbsp;Chengkang Zhang,&nbsp;Qun-Yong Zhou","doi":"10.5334/jcr.170","DOIUrl":"https://doi.org/10.5334/jcr.170","url":null,"abstract":"<p><p>In mammals, the master pacemaker driving circadian rhythms is thought to reside in the suprachiasmatic nuclei (SCN) of the anterior hypothalamus. A clear view of molecular clock mechanisms within the SCN neurons has been elucidated. In contrast, much less is known about the output mechanism by which the SCN circadian pacemaker sends timing information for eventual control of physiological and behavioral rhythms. Two secreted molecules, prokineticin 2 (PK2) and vasopressin, that are encoded by respective clock-controlled genes, have been indicated as candidate SCN output molecules. Several lines of evidence have emerged that support the role of PK2 as an output signal for the SCN circadian clock, including the reduced circadian rhythms in mice that are deficient in PK2 or its receptor, PKR2. In the current study, transgenic mice with the overexpression of PK2 have been generated. These transgenic mice displayed reduced oscillation of the PK2 expression in the SCN and decreased amplitude of circadian locomotor rhythm, supporting the important signaling role of PK2 in the regulation of circadian rhythms. Altered molecular rhythms were also observed in the SCN in the transgenic mice, indicating that PK2 signaling also regulates the operation of core clockwork. This conclusion is consistent with recent reports showing the likely signaling role of PK2 from the intrinsically photosensitive retinal ganglion cells to SCN neurons. Thus, PK2 signaling plays roles in both the input and the output pathways of the SCN circadian clock.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"16 ","pages":"13"},"PeriodicalIF":0.0,"publicationDate":"2018-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6234414/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36764139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intracerebral Adenosine During Sleep Deprivation: A Meta-Analysis and New Experimental Data.","authors":"Cathalijn H C Leenaars,&nbsp;Sergey A Savelyev,&nbsp;Stevie Van der Mierden,&nbsp;Ruud N J M A Joosten,&nbsp;Maurice Dematteis,&nbsp;Tarja Porkka-Heiskanen,&nbsp;Matthijs G P Feenstra","doi":"10.5334/jcr.171","DOIUrl":"https://doi.org/10.5334/jcr.171","url":null,"abstract":"<p><p>The neuroregulator adenosine is involved in sleep-wake control. Basal forebrain (BF) adenosine levels increase during sleep deprivation. Only a few studies have addressed the effect of sleep deprivation on extracellular adenosine concentrations in other brain regions. In this paper, we describe a microdialysis experiment as well as a meta-analysis of published data. The 64 h microdialysis experiment determined the extracellular adenosine and adenosine monophosphate (AMP) concentrations in the medial prefrontal cortex of rats before, during and after 12 h of sleep deprivation by forced locomotion. The meta-analysis comprised published sleep deprivation animal experiments measuring adenosine by means of microdialysis. In the animal experiment, the overall median adenosine concentration was 0.36 nM and ranged from 0.004 nM to 27 nM. No significant differences were observed between the five conditions: 12 h of wash-out, baseline light phase, baseline dark phase, 12 h of sleep deprivation and 12 h of subsequent recovery. The overall median AMP concentration was 0.10 nM and ranged from 0.001 nM to 7.56 nM. Median AMP concentration increased during sleep deprivation (T = 47; p = 0.047) but normalised during subsequent recovery. The meta-analysis indicates that BF dialysate adenosine concentrations increase with 74.7% (95% CI: 54.1-95.3%) over baseline during sleep deprivation. Cortex dialysate adenosine concentrations during sleep deprivation were so far only reported by 2 publications. The increase in adenosine during sleep deprivation might be specific to the BF. At this stage, the evidence for adenosine levels in other brain regions is based on single experiments and insufficient for generalised conclusions. Further experiments are currently still warranted.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"16 ","pages":"11"},"PeriodicalIF":0.0,"publicationDate":"2018-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6196573/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36712486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Systematic Search and Mapping Review of Studies on Intracerebral Microdialysis of Amino Acids, and Systematized Review of Studies on Circadian Rhythms.","authors":"Cathalijn H C Leenaars,&nbsp;Jennifer Freymann,&nbsp;Koen Jakobs,&nbsp;Julia M L Menon,&nbsp;Thomas J Van Ee,&nbsp;Janneke Elzinga,&nbsp;Rosalie W M Kempkes,&nbsp;Bea Zoer,&nbsp;Pim W H I M Drinkenburg","doi":"10.5334/jcr.172","DOIUrl":"https://doi.org/10.5334/jcr.172","url":null,"abstract":"<p><strong>Background: </strong>Microdialysis can be used to measure amino acids in the extracellular space in vivo, based on the principle of diffusion. Variations in experimental set-up result in variations in baseline levels of the compounds measured. Variations may also be due to circadian rhythms.</p><p><strong>Method: </strong>We systematically searched and mapped the literature on all studies reporting baseline microdialysis measurements of histamine and the amino acids asparagine, aspartate, GABA, glutamate, glutamine, glycine, proline and taurine. We fully reviewed the studies describing circadian rhythms for histamine and the selected amino acids.</p><p><strong>Results: </strong>We retrieved 2331 papers describing baseline measurements of one or more of the compounds of interest. We provide a numerical summary and lists of the publications by compound. We retrieved 11 references describing studies on the circadian rhythms of the compounds of interest. Aspartate, glutamate and histamine are generally higher during the dark than during the light phase in nocturnal rodents. For glutamine, no rhythmicity was observed. For GABA, the results were too inconsistent to generalise. For asparagine, glycine, proline and taurine, insufficient data are available.</p><p><strong>Conclusion: </strong>The literature on intracerebral microdialysis measurements of the amino acids is vast, but certain primary studies are still warranted. Future systematic reviews on the individual compounds can shed light on the effects of experimental variations on baseline concentrations.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"16 ","pages":"12"},"PeriodicalIF":0.0,"publicationDate":"2018-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6196574/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36712488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using the Analytic Network Process Method for Prioritizing and Weighing Shift Work Disorders Among the Personnel of Hospitals of Kerman University of Medical Sciences.","authors":"Sajad Zare,&nbsp;Hossein Elahi Shirvan,&nbsp;Rasoul Hemmatjo,&nbsp;Mohammad Faridan,&nbsp;Masoud Hajghani,&nbsp;Behzad Fouladi Dehaghi","doi":"10.5334/jcr.163","DOIUrl":"https://doi.org/10.5334/jcr.163","url":null,"abstract":"<p><strong>Introduction: </strong>Increasing population, the need for services, and industrialization of societies have led to a growing demand for shift work. Shiftwork causes several disorders, and determining the weight of each disorders is important for their prevention and treatment. Therefore, the purpose of the present study was to use Analytic Network Process (ANP) to prioritize and weigh shift work disorders among the personnel of hospitals of Kerman University of Medical Sciences.</p><p><strong>Methods: </strong>This cross-sectional, descriptive-analytical study was conducted in 2017 among 300 shift work personnel of 10 public hospitals affiliated with Kerman University of Medical Sciences. ANP was used to prioritize and weigh shift work disorders. To this end, the criteria, sub-criteria, and alternatives were initially identified. Then, shift work disorders were categorized into 7 general criteria, 20 sub-criteria, and 3 alternatives. After designing the ANP and determining the effect of each criterion on the sub-criteria, the ANP questionnaire was developed and administered among the shift work personnel, who filled it out based on ANP. Super Decisions was subsequently used to weigh and prioritize shift work disorders.</p><p><strong>Results: </strong>The results indicated that shift work disorders among the nurses included sleep disorders (0.297), psychological disorders (0.275), digestive disorders (0.137), personal life disorders (0.122), etc., in that order of weighing. With respect to the support staff, the major shift work disorders involved sleep disorders (0.252), digestive disorders (0.198), personal life disorders (0.168), and psychological disorders (0.164). Considering security personnel, the top four shift work disorders were sleep disorders (0.201), digestive disorders (0.186), psychological disorders (0.174), and personal life disorders (0.145).</p><p><strong>Conclusion: </strong>According to the findings, sleep disorders had the highest weight in the three studied groups. Moreover, the night shift had the most profound effect on shift work disorders among the personnel in the three groups. It was followed by the evening shift. Morning shift had the lowest influence on shift work disorders. Therefore, the schedules should be taken to prevent these complications in the shift workers. It is suggested that work shift complications be included in the periodic examination program and, in case of discovery of any rhythmic disorder in each shift workers, the person should not remain in the shiftwork group for some time.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"16 ","pages":"10"},"PeriodicalIF":0.0,"publicationDate":"2018-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5334/jcr.163","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36631968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-Image Forming Effects of Light on Brainwaves, Autonomic Nervous Activity, Fatigue, and Performance.","authors":"Taleb Askaripoor,&nbsp;Majid Motamedzadeh,&nbsp;Rostam Golmohammadi,&nbsp;Maryam Farhadian,&nbsp;Mohammad Babamiri,&nbsp;Mehdi Samavati","doi":"10.5334/jcr.167","DOIUrl":"https://doi.org/10.5334/jcr.167","url":null,"abstract":"<p><p>Fatigue and sleepiness are one of the main causes of human errors and accidents in the workplace. The empirical evidence has approved that, in addition to stimulating the visual system, light elicits brain responses, which affect physiological and neurobehavioral human functions, known as the non-image forming (NIF) effects of light. As recent evidences have shown the positive effects of red or low correlated color temperature white light on alertness and performance, we investigated whether exposure to 2564 K light could improve subjective and objective measures of alertness and performance compared with 7343 K, 3730 K, and dim light (DL) conditions during the daytime. Twenty two healthy participants were exposed to the light while they were performing a sustained attention task and their electroencephalogram (EEG) and electrocardiogram (ECG) were recorded. Both 2564 K and 7343 K conditions significantly reduced EEG alpha-power compared with the DL and 3730 K conditions. Moreover, the 2564 K, 7343 K, and 3730 K conditions significantly reduced subjective fatigue, sleepiness and increased heart rate and performance compared with the DL condition. Furthermore, the effects of light conditions on alertness and performance varied over the day so that more effective responses were observed during the afternoon hours. These findings suggest that light interventions can be applied to improve daytime performance.</p>","PeriodicalId":15461,"journal":{"name":"Journal of Circadian Rhythms","volume":"16 ","pages":"9"},"PeriodicalIF":0.0,"publicationDate":"2018-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6137608/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36491749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}