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Author (up) Madahi, P.-G.; Ivan, O.; Adriana, B.; Diana, O.; Carolina, E. url  doi
openurl 
  Title Constant light during lactation programs circadian and metabolic systems Type Journal Article
  Year 2018 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 35 Issue 8 Pages 1153-1167  
  Keywords Animals  
  Abstract Exposure to light at night is a disruptive condition for the adult circadian system, leading to arrhythmicity in nocturnal rodents. Circadian disruption is a risk factor for developing physiological and behavioral alterations, including weight gain and metabolic disease. During early stages of development, the circadian system undergoes a critical period of adjustment, and it is especially vulnerable to altered lighting conditions that may program its function, leading to long-term effects. We hypothesized that during lactation a disrupted light-dark cycle due to light at night may disrupt the circadian system and in the long term induce metabolic disorders. Here we explored in pups, short- and long-term effects of constant light (LL) during lactation. In the short term, LL caused a loss of rhythmicity and a reduction in the immunopositive cells of VIP, AVP, and PER1 in the suprachiasmatic nucleus (SCN). In the short term, the affection on the circadian clock in the pups resulted in body weight gain, loss of daily rhythms in general activity, plasma glucose and triglycerides (TG). Importantly, the DD conditions during development also induced altered daily rhythms in general activity and in the SCN. Exposure to LD conditions after lactation did not restore rhythmicity in the SCN, and the number of immunopositve cells to VIP, AVP, and PER1 remained reduced. In the long term, daily rhythmicity in general activity was restored; however, daily rhythms in glucose and TG remained disrupted, and daily mean levels of TG were significantly increased. Present results point out the programming role played by the LD cycle during early development in the function of the circadian system and on metabolism. This study points out the risk represented by exposure to an altered light-dark cycle during early stages of development. ABBREVIATIONS: AVP: arginine vasopressin peptide; CRY: cryptochrome; DD: constant darkness; DM: dorsomedial; LD: light-dark cycle; LL: constant light; NICUs: neonatal intensive care units; P: postnatal days; PER: period; S.E.M.: standard error of the mean; SCN: suprachiasmatic nucleus; TG: triglycerides; VIP: vasointestinal peptide; VL: ventrolateral; ZT: zeitgeber time.  
  Address a Facultad de Medicina , Universidad Nacional Autonoma de Mexico, UNAM , Mexico City , 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 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:29688088 Approved no  
  Call Number GFZ @ kyba @ Serial 1884  
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Author (up) Maroni, M.J.; Capri, K.M.; Arruda, N.L.; Gelineau, R.R.; Deane, H.V.; Concepcion, H.A.; DeCourcey, H.; Monteiro De Pina, I.K.; Cushman, A.V.; Chasse, M.H.; Logan, R.W.; Seggio, J.A. url  doi
openurl 
  Title Substrain specific behavioral responses in male C57BL/6N and C57BL/6J mice to a shortened 21-hour day and high-fat diet Type Journal Article
  Year 2020 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume in press Issue Pages  
  Keywords Animals; Mouse; circadian; high-fat diet; locomotor activity; photoperiod; strain differences  
  Abstract Altered circadian rhythms have negative consequences on health and behavior. Emerging evidence suggests genetics influences the physiological and behavioral responses to circadian disruption. We investigated the effects of a 21 h day (T = 21 cycle), with high-fat diet consumption, on locomotor activity, explorative behaviors, and health in male C57BL/6J and C57BL/6N mice. Mice were exposed to either a T = 24 or T = 21 cycle and given standard rodent chow (RC) or a 60% high-fat diet (HFD) followed by behavioral assays and physiological measures. We uncovered numerous strain differences within the behavioral and physiological assays, mainly that C57BL/6J mice exhibit reduced susceptibility to the obesogenic effects of (HFD) and anxiety-like behavior as well as increased circadian and novelty-induced locomotor activity compared to C57BL/6N mice. There were also substrain-specific differences in behavioral responses to the T = 21 cycle, including exploratory behaviors and circadian locomotor activity. Under the 21-h day, mice consuming RC displayed entrainment, while mice exposed to HFD exhibited a lengthening of activity rhythms. In the open-field and light-dark box, mice exposed to the T = 21 cycle had increased novelty-induced locomotor activity with no further effects of diet, suggesting daylength may affect mood-related behaviors. These results indicate that different circadian cycles impact metabolic and behavioral responses depending on genetic background, and despite circadian entrainment.  
  Address Department of Biological Sciences, Bridgewater State University, Bridgewater, Massachusetts, USA  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:32400203 Approved no  
  Call Number GFZ @ kyba @ Serial 2919  
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Author (up) Maroni, M.J.; Capri, K.M.; Cushman, A.V.; Monteiro De Pina, I.K.; Chasse, M.H.; Seggio, J.A. url  doi
openurl 
  Title Constant light alters serum hormone levels related to thyroid function in male CD-1 mice Type Journal Article
  Year 2018 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 35 Issue 10 Pages 1456-1463  
  Keywords Animals  
  Abstract Disruptions to the circadian rhythm can lead to altered metabolism. Modification of thyroid function may be a reason why circadian misalignment may contribute to future metabolic disorders. We investigated whether circadian disruption through constant light (LL) can lead to variations in hormone levels associated with thyroid function. Mice were exposed to LL or a 12:12 Light:Dark (LD) cycle for 6 weeks; then glucose tolerance and thyroid hormone levels were measured at ZT 6 and ZT 18. There was day/night variation in glucose tolerance, but LL had no effect. LL reduced TSH, increased fT4, and abolished day/night variation in fT3 and leptin. These findings illustrate that LL alters thyroid-related hormones, providing evidence of a link between circadian disruption and thyroid function.  
  Address a Department of Biological Sciences , Bridgewater State University , Bridgewater , MA , 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 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:29953263 Approved no  
  Call Number GFZ @ kyba @ Serial 1958  
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Author (up) Martinez-Nicolas, A.; Madrid, J.A.; Rol, M.A. url  doi
openurl 
  Title Day-night contrast as source of health for the human circadian system Type Journal Article
  Year 2014 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 31 Issue 3 Pages 382-393  
  Keywords Human Health  
  Abstract Modern societies are characterized by a 24/7 lifestyle (LS) with no environmental differences between day and night, resulting in weak zeitgebers (weak day light, absence of darkness during night, constant environmental temperature, sedentary LS and frequent snacking), and as a consequence, in an impaired circadian system (CS) through a process known as chronodisruption. Both weak zeitgebers and CS impairment are related to human pathologies (certain cancers, metabolic syndrome and affective and cognitive disorders), but little is known about how to chronoenhance the CS. The aim of this work is to propose practical strategies for chronoenhancement, based on accentuating the day/night contrast. For this, 131 young subjects were recruited, and their wrist temperature (WT), activity, body position, light exposure, environmental temperature and sleep were recorded under free-living conditions for 1 week. Subjects with high contrast (HC) and low contrast (LC) for each variable were selected to analyze the HC effect in activity, body position, environmental temperature, light exposure and sleep would have on WT. We found that HC showed better rhythms than LC for every variable except sleep. Subjects with HC and LC for WT also demonstrated differences in LS, where HC subjects had a slightly advanced night phase onset and a general increase in day/night contrast. In addition, theoretical high day/night contrast calculated using mathematical models suggests an improvement by means of LS contrast. Finally, some individuals classified as belonging to the HC group in terms of WT when they are exposed to the LS characteristic of the LC group, while others exhibit WT arrhythmicity despite their good LS habits, revealing two different WT components: an exogenous component modified by LS and another endogenous component that is refractory to it. Therefore, intensifying day/night contrast in subject's LS has proven to be a feasible measure to chronoenhance the CS.  
  Address Chronobiology Laboratory, Department of Physiology, College of Biology, University of Murcia , 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 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:24304407 Approved no  
  Call Number LoNNe @ kagoburian @ Serial 780  
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Author (up) Martinez-Nicolas, A.; Ortiz-Tudela, E.; Madrid, J.A.; Rol, M.A. url  doi
openurl 
  Title Crosstalk between environmental light and internal time in humans Type Journal Article
  Year 2011 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 28 Issue 7 Pages 617-629  
  Keywords Adolescent; Biological Clocks/*physiology; Circadian Rhythm/*physiology; Cues; *Environment; Female; Humans; *Light; Male; Sleep; Spain; Temperature; *Time; Young Adult  
  Abstract Daily exposure to environmental light is the most important zeitgeber in humans, and all studied characteristics of light pattern (timing, intensity, rate of change, duration, and spectrum) influence the circadian system. However, and due to lack of current studies on environmental light exposure and its influence on the circadian system, the aim of this work is to determine the characteristics of a naturalistic regimen of light exposure and its relationship with the functioning of the human circadian system. Eighty-eight undergraduate students (18-23 yrs) were recruited in Murcia, Spain (latitude 38 degrees 01'N) to record wrist temperature (WT), light exposure, and sleep for 1 wk under free-living conditions. Light-exposure timing, rate of change, regularity, intensity, and contrast were calculated, and their effects on the sleep pattern and WT rhythm were then analyzed. In general, higher values for interdaily stability, relative amplitude, mean morning light, and light quality index (LQI) correlated with higher interdaily stability and relative amplitude, and phase advance in sleep plus greater stability in WT and phase advance of the WT circadian rhythm. On the other hand, a higher fragmentation of the light-exposure rhythm was associated with more fragmented sleep. Naturalistic studies using 24-h ambulatory light monitoring provide essential information about the main circadian system input, necessary for maintaining healthy circadian tuning. Correcting light-exposure patterns accordingly may help prevent or even reverse health problems associated with circadian disruption.  
  Address Chronobiology Laboratory, Department of Physiology, University of Murcia, 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 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:21793693 Approved no  
  Call Number IDA @ john @ Serial 302  
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Author (up) Matsumoto, S.-I.; Shirahashi, K. url  doi
openurl 
  Title Novel perspectives on the influence of the lunar cycle on the timing of full-term human births Type Journal Article
  Year 2020 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume in press Issue Pages  
  Keywords Moonlight; Human birth; full moon; lunar cycle; new moon  
  Abstract It is claimed by some that the number of births occurring at the time of the full moon is greater than other phases of the lunar cycle; however, many publications fail to substantiate the claim leading to the conclusion it is myth. We tested using a novel approach the null hypotheses: (i) human birth is not lunar cycle-dependent and (ii) the number of births occurring at or around the time of the full moon is not different from the number occurring at the time of the other phases of the lunar cycle. We reviewed the birth records from 1 January 1996 to 16 March 2007 of the obstetric department of our hospital, which was then located in a relatively undeveloped area of Fukutsu city in Fukuoka Prefecture of southern Japan. A total of 1507 births satisfied all inclusion criteria, among others, being full-term and following spontaneously initiated labor. When the birth data were analyzed as done by other investigators, i.e. total number of births per lunar day, lunar phase was not found to be influential. However, more detailed analyses on the subset of babies born specifically during the nighttime hours (N = 362) revealed the number of births varied in relation specifically to the changing amount of moonlight during the nighttime at different stages of the lunar cycle, with highest number of births at or around the time of the full moon. In contrast, analyses on the subset of babies born specifically during the daytime hours (N = 377) revealed the number of births varied in relation specifically to the changing amount moonlight during the daytime at different stages of the lunar cycle, with the highest number of births at or around the time of the new moon. The initiation and culmination of human birth are typically a nocturnal process. The findings of this investigation are consistent with the hypothesis natural nighttime parturition is influenced by lunar phase, particularly the full moon, and, thus, they are consistent with the belief the moon exerts an affect upon the timing of human birth. We speculate the long-hold belief of the association between birth and lunar phase may be based on historical observations that in the absence of artificial light at night nocturnal births occurred in elevated number when the full moon brightly illuminated the nighttime sky.  
  Address Department of Obstetrics and Gynecology, Munakata Suikokai General Hospital , Fukutsu, Fukuoka Prefecture, 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 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:32703035 Approved no  
  Call Number GFZ @ kyba @ Serial 3083  
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Author (up) Monk, T.H.; Kupfer, D.J. url  doi
openurl 
  Title Circadian Rhythms In Healthy Aging--Effects Downstream From The Pacemaker Type Journal Article
  Year 2000 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 17 Issue 3 Pages 355-368  
  Keywords Human Health  
  Abstract  
  Address  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ kagoburian @ Serial 783  
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Author (up) Obayashi, K.; Saeki, K.; Iwamoto, J.; Ikada, Y.; Kurumatani, N. url  doi
openurl 
  Title Association between light exposure at night and nighttime blood pressure in the elderly independent of nocturnal urinary melatonin excretion Type Journal Article
  Year 2014 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 31 Issue 6 Pages 779-786  
  Keywords Actigraphy; circadian rhythm; elderly; light at night; melatonin; nighttime blood pressure; geriatrics  
  Abstract Circadian misalignment between internal and environmental rhythms dysregulates blood pressure (BP) variability because of disruption of the biological clock, resulting in increased nighttime BP. Although exposure to light-at-night is associated with the circadian misalignment, it remains unclear whether exposure to light-at-night in home settings is associated with nighttime BP. In this cross-sectional analysis of 528 elderly individuals (mean age: 72.8 years), we measured bedroom light intensity at 1-min intervals on two consecutive nights along with ambulatory BP, overnight urinary melatonin excretion and actigraphy. With regard to adjusted mean comparisons using analysis of covariance, the light-at-night group (average: >/=5 lux; n = 109) showed significantly higher nighttime systolic BP (SBP; adjusted mean: 120.8 vs. 116.5 mmHg, p = 0.01) and diastolic BP (70.1 vs. 67.1 mmHg, p < 0.01) compared with the Darker group (average: <5 lux; n = 419) independently of potential confounding factors including overnight urinary melatonin excretion and actigraphic sleep quality. We observed consistent associations between light-at-night and nighttime BP in different cutoff values for light-at-night intensity (i.e. 3 and 10 lux). In conclusion, exposure to light-at-night in home settings is significantly associated with increased nighttime BP in elderly individuals independently of overnight urinary melatonin excretion. A 4.3 mmHg increase in nighttime SBP is associated with a 6.1% increase in total mortality, which corresponds to approximately 10 000 annual excess deaths in Japanese elderly population.  
  Address Department of Community Health and Epidemiology, Nara Medical University School of Medicine , Nara , Japan  
  Corporate Author Thesis  
  Publisher Informa Plc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:24673296 Approved no  
  Call Number IDA @ john @ Serial 315  
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Author (up) Phipps-Nelson, J.; Redman, J.R.; Schlangen, L.J.M.; Rajaratnam, S.M.W. url  doi
openurl 
  Title Blue light exposure reduces objective measures of sleepiness during prolonged nighttime performance testing Type Journal Article
  Year 2009 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 26 Issue 5 Pages 891-912  
  Keywords Human Health  
  Abstract This study examined the effects of nocturnal exposure to dim, narrowband blue light (460 nm, approximately 1 lux, 2 microW/cm2), compared to dim broad spectrum (white) ambient light ( approximately 0.2 lux, 0.5 microW/cm2), on subjective and objective indices of sleepiness during prolonged nighttime performance testing. Participants were also exposed to a red light (640 nm, approximately 1 lux, 0.7 microW/cm2) placebo condition. Outcome measures were driving simulator and psychomotor vigilance task (PVT) performance, subjective sleepiness, salivary melatonin, and electroencephalographic (EEG) activity. The study had a repeated-measures design, with three counterbalanced light conditions and a four-week washout period between each condition. Participants (n = 8) maintained a regular sleep-wake schedule for 14 days prior to the approximately 14 h laboratory study, which consisted of habituation to light conditions followed by neurobehavioral performance testing from 21:00 to 08:30 h under modified constant-routine conditions. A neurobehavioral test battery (2.5 h) was presented four times between 21:00 and 08:30 h, with a 30 min break between each. From 23:30 to 05:30 h, participants were exposed to blue or red light, or remained in ambient conditions. Compared to ambient light exposure, blue light exposure suppressed EEG slow wave delta (1.0-4.5 Hz) and theta (4.5-8 Hz) activity and reduced the incidence of slow eye movements. PVT reaction times were significantly faster in the blue light condition, but driving simulator measures, subjective sleepiness, and salivary melatonin levels were not significantly affected by blue light. Red light exposure, as compared to ambient light exposure, reduced the incidence of slow eye movements. The results demonstrate that low-intensity, blue light exposure can promote alertness, as measured by some of the objective indices used in this study, during prolonged nighttime performance testing. Low intensity, blue light exposure has the potential to be applied to situations where it is desirable to increase alertness but not practical or appropriate to use bright light, such as certain occupational settings.  
  Address School of Psychology, Psychiatry and Psychological Medicine, Monash University, Clayton, Victoria, Australia  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:19637049 Approved no  
  Call Number GFZ @ kyba @ Serial 2202  
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Author (up) Porcheret, K.; Wald, L.; Fritschi, L.; Gerkema, M.; Gordijn, M.; Merrrow, M.; Rajaratnam, S.M.W.; Rock, D.; Sletten, T.L.; Warman, G.; Wulff, K.; Roenneberg, T.; Foster, R.G. url  doi
openurl 
  Title Chronotype and environmental light exposure in a student population Type Journal Article
  Year 2018 Publication Chronobiology International Abbreviated Journal Chronobiol Int  
  Volume 35 Issue 10 Pages 1365-1374  
  Keywords Human Health  
  Abstract In humans and most other species, changes in the intensity and duration of light provide a critical set of signals for the synchronisation of the circadian system to the astronomical day. The timing of activity within the 24 h day defines an individual's chronotype, i.e. morning, intermediate or evening type. The aim of this study was to investigate the associations between environmental light exposure, due to geographical location, on the chronotype of university students. Over 6 000 university students from cities in the Northern Hemisphere (Oxford, Munich and Groningen) and Southern Hemisphere (Perth, Melbourne and Auckland) completed the Munich ChronoType Questionnaire. In parallel, light measures (daily irradiance, timing of sunrise and sunset) were compiled from satellite or ground stations at each of these locations. Our data shows that later mid-sleep point on free days (corrected for oversleep on weekends MFSsc) is associated with (i) residing further from the equator, (ii) a later sunset, (iii) spending more time outside and (iv) waking from sleep significantly after sunrise. However, surprisingly, MSFsc did not correlate with daily light intensity at the different geographical locations. Although these findings appear to contradict earlier studies suggesting that in the wider population increased light exposure is associated with an earlier chronotype, our findings are derived exclusively from a student population aged between 17 and 26 years. We therefore suggest that the age and occupation of our population increase the likelihood that these individuals will experience relatively little light exposure in the morning whilst encountering more light exposure later in the day, when light has a delaying effect upon the circadian system.  
  Address a Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences , University of Oxford , Oxford , UK  
  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 0742-0528 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:29913073 Approved no  
  Call Number GFZ @ kyba @ Serial 1962  
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