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Ohayon MM, Stolc V, Freund FT, Milesi C, Sullivan SS. The potential for impact of man-made super low and extremely low frequency electromagnetic fields on sleep. Sleep Med Rev 2019; 47:28-38. [PMID: 31252334 DOI: 10.1016/j.smrv.2019.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/30/2019] [Accepted: 06/04/2019] [Indexed: 01/10/2023]
Abstract
An ever-growing number of electromagnetic (EM) emission sources elicits health concerns, particularly stemming from the ubiquitous low to extremely low frequency fields from power lines and appliances, and the radiofrequency fields emitted from telecommunication devices. In this article we review the state of knowledge regarding possible impacts of electromagnetic fields on melatonin secretion and on sleep structure and the electroencephalogram of humans. Most of the studies on the effects of melatonin on humans have been conducted in the presence of EM fields, focusing on the effects of occupational or residential exposures. While some of the earlier studies indicated that EM fields may have a suppressive effect on melatonin, the results cannot be generalized because of the large variability in exposure conditions and other factors that may influence melatonin. For instance, exposure to radiofrequency EM fields on sleep architecture show little or no effect. However, a number of studies show that pulsating radiofrequency electromagnetic fields, such as those emitted from cellular phones, can alter brain physiology, increasing the electroencephalogram power in selective bands when administered immediately prior to or during sleep. Additional research is necessary that would include older populations and evaluate the interactions of EM fields in different frequency ranges to examine their effects on sleep in humans.
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Affiliation(s)
- Maurice M Ohayon
- Stanford Sleep Epidemiology Research Center, Stanford University, School of Medicine, Palo Alto, CA, 94303, USA.
| | - Victor Stolc
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
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Facer-Childs ER, Middleton B, Skene DJ, Bagshaw AP. Resetting the late timing of 'night owls' has a positive impact on mental health and performance. Sleep Med 2019; 60:236-247. [PMID: 31202686 DOI: 10.1016/j.sleep.2019.05.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/01/2019] [Accepted: 05/03/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND There is conflict between living according to our endogenous biological rhythms and our external environment, with disruptions resulting in negative consequences to health and performance. This is often documented in shift work and jet lag, but 'societal norms' (eg, typical working hours) can create profound issues for 'night owls', people whose internal biological timing predisposes them to follow an unusually late sleep-wake cycle. Night owls have also been associated with health issues, mood disturbances, poorer performance and increased mortality rates. METHODS This study used a randomized control trial design aimed to shift the late timing of night owls to an earlier time (phase advance), using non-pharmacological, practical interventions in a real-world setting. These interventions targeted light exposure (through earlier wake up/sleep times), fixed meals times, caffeine intake and exercise. RESULTS Overall, participants demonstrated a significant advance of ∼2 h in sleep/wake timings as measured by actigraphy and circadian phase markers (dim light melatonin onset and peak time of the cortisol awakening response), whilst having no adverse effect on sleep duration. Notably, the phase advance was accompanied by significant improvements to self-reported depression and stress, as well as improved cognitive (reaction time) and physical (grip strength) performance measures during the typical 'suboptimal' morning hours. CONCLUSIONS Our findings propose a novel strategy for shifting clock timing towards a pattern that is more aligned to societal demands that could significantly improve elements of performance, mental health and sleep timing in the real world.
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Affiliation(s)
- Elise R Facer-Childs
- School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK; Centre for Human Brain Health, University of Birmingham, Birmingham, B15 2TT, UK; School of Psychology, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Benita Middleton
- Faculty of Health & Medical Sciences, University of Surrey, Guildford, GU2 7XH, UK
| | - Debra J Skene
- Faculty of Health & Medical Sciences, University of Surrey, Guildford, GU2 7XH, UK
| | - Andrew P Bagshaw
- Centre for Human Brain Health, University of Birmingham, Birmingham, B15 2TT, UK; School of Psychology, University of Birmingham, Birmingham, B15 2TT, UK
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Slanger TE, Gross JV, Pinger A, Morfeld P, Bellinger M, Duhme A, Reichardt Ortega RA, Costa G, Driscoll TR, Foster RG, Fritschi L, Sallinen M, Liira J, Erren TC. Person-directed, non-pharmacological interventions for sleepiness at work and sleep disturbances caused by shift work. Cochrane Database Syst Rev 2016; 2016:CD010641. [PMID: 27549931 PMCID: PMC8406755 DOI: 10.1002/14651858.cd010641.pub2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Shift work is often associated with sleepiness and sleep disorders. Person-directed, non-pharmacological interventions may positively influence the impact of shift work on sleep, thereby improving workers' well-being, safety, and health. OBJECTIVES To assess the effects of person-directed, non-pharmacological interventions for reducing sleepiness at work and improving the length and quality of sleep between shifts for shift workers. SEARCH METHODS We searched CENTRAL, MEDLINE Ovid, Embase, Web of Knowledge, ProQuest, PsycINFO, OpenGrey, and OSH-UPDATE from inception to August 2015. We also screened reference lists and conference proceedings and searched the World Health Organization (WHO) Trial register. We contacted experts to obtain unpublished data. SELECTION CRITERIA Randomised controlled trials (RCTs) (including cross-over designs) that investigated the effect of any person-directed, non-pharmacological intervention on sleepiness on-shift or sleep length and sleep quality off-shift in shift workers who also work nights. DATA COLLECTION AND ANALYSIS At least two authors screened titles and abstracts for relevant studies, extracted data, and assessed risk of bias. We contacted authors to obtain missing information. We conducted meta-analyses when pooling of studies was possible. MAIN RESULTS We included 17 relevant trials (with 556 review-relevant participants) which we categorised into three types of interventions: (1) various exposures to bright light (n = 10); (2) various opportunities for napping (n = 4); and (3) other interventions, such as physical exercise or sleep education (n = 3). In most instances, the studies were too heterogeneous to pool. Most of the comparisons yielded low to very low quality evidence. Only one comparison provided moderate quality evidence. Overall, the included studies' results were inconclusive. We present the results regarding sleepiness below. Bright light Combining two comparable studies (with 184 participants altogether) that investigated the effect of bright light during the night on sleepiness during a shift, revealed a mean reduction 0.83 score points of sleepiness (measured via the Stanford Sleepiness Scale (SSS) (95% confidence interval (CI) -1.3 to -0.36, very low quality evidence). Another trial did not find a significant difference in overall sleepiness on another sleepiness scale (16 participants, low quality evidence).Bright light during the night plus sunglasses at dawn did not significantly influence sleepiness compared to normal light (1 study, 17 participants, assessment via reaction time, very low quality evidence).Bright light during the day shift did not significantly reduce sleepiness during the day compared to normal light (1 trial, 61 participants, subjective assessment, low quality evidence) or compared to normal light plus placebo capsule (1 trial, 12 participants, assessment via reaction time, very low quality evidence). Napping during the night shiftA meta-analysis on a single nap opportunity and the effect on the mean reaction time as a surrogate for sleepiness, resulted in a 11.87 ms reduction (95% CI 31.94 to -8.2, very low quality evidence). Two other studies also reported statistically non-significant decreases in reaction time (1 study seven participants; 1 study 49 participants, very low quality evidence).A two-nap opportunity resulted in a statistically non-significant increase of sleepiness (subjective assessment) in one study (mean difference (MD) 2.32, 95% CI -24.74 to 29.38, 1 study, 15 participants, low quality evidence). Other interventionsPhysical exercise and sleep education interventions showed promise, but sufficient data to draw conclusions are lacking. AUTHORS' CONCLUSIONS Given the methodological diversity of the included studies, in terms of interventions, settings, and assessment tools, their limited reporting and the very low to low quality of the evidence they present, it is not possible to determine whether shift workers' sleepiness can be reduced or if their sleep length or quality can be improved with these interventions.We need better and adequately powered RCTs of the effect of bright light, and naps, either on their own or together and other non-pharmacological interventions that also consider shift workers' chronobiology on the investigated sleep parameters.
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Affiliation(s)
- Tracy E Slanger
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - J. Valérie Gross
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Andreas Pinger
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Peter Morfeld
- Evonik Technology & Infrastructure GmbHInstitute for Occupational Epidemiology and Risk Assessment (IERA)Rellinghauser Str. 1‐11EssenGermany45128
| | - Miriam Bellinger
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Anna‐Lena Duhme
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Rosalinde Amancay Reichardt Ortega
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
| | - Giovanni Costa
- University of MilanDepartment of Clinical Sciences and Community HealthVia S. Barnaba 8MilanItaly20122
| | - Tim R Driscoll
- The University of SydneySchool of Public HealthEdward Ford Building (A27)SydneyNew South WalesAustralia2006
| | - Russell G Foster
- University of OxfordNuffield Department of Clinical Neurosciences; Circadian and Visual NeuroscienceLevel 6, West Wing, The John Radcliffe HospitalHeadley WayOxfordUKOX3 9DU
| | - Lin Fritschi
- Curtin UniversitySchool of Public Health35 Stirling HighwayPerthWest AustraliaAustralia6152
| | - Mikael Sallinen
- Finnish Institute of Occupational HealthCentre of Expertise for the Development of Work and Organizations / Working Hours, Alertness, and Professional Traffic teamTopeliuksenkatu 41 a AHelsinkiFinlandFI‐00250
| | - Juha Liira
- Finnish Institute of Occupational HealthResearch and Development in Occupational Health ServicesTopeliuksenkatu 41 a AHelsinkiFinlandFI‐00250
| | - Thomas C Erren
- University of CologneInstitute and Policlinic for Occupational Medicine, Environmental Medicine and Preventive ResearchKerpener Str. 62CologneGermany50937
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Boivin DB, Boudreau P, James FO, Kin NMKNY. Photic resetting in night-shift work: impact on nurses' sleep. Chronobiol Int 2012; 29:619-28. [PMID: 22621359 DOI: 10.3109/07420528.2012.675257] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The objective of this study was to quantify daytime sleep in night-shift workers with and without an intervention designed to recover the normal relationship between the endogenous circadian pacemaker and the sleep/wake cycle. Workers of the treatment group received intermittent exposure to full-spectrum bright light during night shifts and wore dark goggles during the morning commute home. All workers maintained stable 8-h daytime sleep/darkness schedules. The authors found that workers of the treatment group had daytime sleep episodes that lasted 7.1 ± .1 h (mean ± SEM) versus 6.6 ± .2 h for workers in the control group (p = .04). The increase in total sleep time co-occurred with a larger proportion of the melatonin secretory episode during daytime sleep in workers of the treatment group. The results of this study showed reestablishment of a phase angle that is comparable to that observed on a day-oriented schedule favors longer daytime sleep episodes in night-shift workers. (Author correspondence: diane.boivin@douglas.mcgill.ca ).
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Affiliation(s)
- Diane B Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montréal, Québec, Canada.
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Treatment of advanced hepatocellular carcinoma with very low levels of amplitude-modulated electromagnetic fields. Br J Cancer 2011; 105:640-8. [PMID: 21829195 PMCID: PMC3188936 DOI: 10.1038/bjc.2011.292] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background: Therapeutic options for patients with advanced hepatocellular carcinoma (HCC) are limited. There is emerging evidence that the growth of cancer cells may be altered by very low levels of electromagnetic fields modulated at specific frequencies. Methods: A single-group, open-label, phase I/II study was performed to assess the safety and effectiveness of the intrabuccal administration of very low levels of electromagnetic fields amplitude modulated at HCC-specific frequencies in 41 patients with advanced HCC and limited therapeutic options. Three-daily 60-min outpatient treatments were administered until disease progression or death. Imaging studies were performed every 8 weeks. The primary efficacy end point was progression-free survival ⩾6 months. Secondary efficacy end points were progression-free survival and overall survival. Results: Treatment was well tolerated and there were no NCI grade 2, 3 or 4 toxicities. In all, 14 patients (34.1%) had stable disease for more than 6 months. Median progression-free survival was 4.4 months (95% CI 2.1–5.3) and median overall survival was 6.7 months (95% CI 3.0–10.2). There were three partial and one near complete responses. Conclusion: Treatment with intrabuccally administered amplitude-modulated electromagnetic fields is safe, well tolerated, and shows evidence of antitumour effects in patients with advanced HCC.
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Lahti T, Terttunen J, Leppämäki S, Lönnqvist J, Partonen T. Field trial of timed bright light exposure for jet lag among airline cabin crew. Int J Circumpolar Health 2007; 66:365-9. [DOI: 10.3402/ijch.v66i4.18280] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Tuuli Lahti
- National Public Health Institute, Department of Mental Health and Alcohol Research, FI-00300, Helsinki, Finland
| | - Jukka Terttunen
- Finnair Health Services, HEL-IH/67, FI-01053 Finnair, Finland
| | - Sami Leppämäki
- National Public Health Institute, Department of Mental Health and Alcohol Research, FI-00300, Helsinki, Finland
- Helsinki University Central Hospital, Department of Psychiatry, P.O.Box 442, FI-00029 HUS, Finland
| | - Jouko Lönnqvist
- National Public Health Institute, Department of Mental Health and Alcohol Research, FI-00300, Helsinki, Finland
- University of Helsinki, Department of Psychiatry, P.O. Box 22, FI-00014 University of Helsinki, Finland
| | - Timo Partonen
- National Public Health Institute, Department of Mental Health and Alcohol Research, FI-00300, Helsinki, Finland
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Boivin DB, Tremblay GM, James FO. Working on atypical schedules. Sleep Med 2007; 8:578-89. [PMID: 17481949 DOI: 10.1016/j.sleep.2007.03.015] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Revised: 03/13/2007] [Accepted: 03/15/2007] [Indexed: 10/23/2022]
Abstract
Shift work has been associated with a number of health problems including cardiovascular disease, impaired glucose and lipid metabolism, gastrointestinal discomfort, reproductive difficulties, and breast cancer. The specific contributions of disturbed physiological rhythms, circadian misalignment, and sleep debt to the various medical problems encountered by shift workers remain to be clarified. Fatigue can be caused by extended on-duty and/or waking periods, inadequate sleep quantity, sleep disturbances, disruption of circadian rhythms, and difficult work and familial conditions. Fatigue-related accidents raise a safety concern for shift workers, especially at the end of the night when the circadian nadir of alertness interacts with increased time awake. Individuals vary greatly in their capacity to adjust to atypical work schedules and their tolerance to circadian misalignment. Predisposing individual and domestic factors have been identified, such as increasing age, being a single woman in charge of children, and split sleep patterns, all of which can affect the ability to adjust to atypical schedules. However, prior studies indicate that predisposing individual and social determinants are generally poor predictors of shift work tolerance in a given individual. In this manuscript, we review several countermeasures to improve adaptation to shift work.
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Affiliation(s)
- Diane B Boivin
- Centre for Study and Treatment of Circadian Rhythms, Douglas Hospital Research Centre, 6875 LaSalle Boulevard, F-1127 Montreal, Que., Canada H4H 1R3.
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Hansen M, Janssen I, Schiff A, Zee PC, Dubocovich ML. The impact of school daily schedule on adolescent sleep. Pediatrics 2005; 115:1555-61. [PMID: 15930216 DOI: 10.1542/peds.2004-1649] [Citation(s) in RCA: 174] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES This study was initiated to examine the impact of starting school on adolescent sleep, to compare weekday and weekend sleep times, and to attempt to normalize the timing of the circadian sleep/wake cycle by administering bright light in the morning. This was a collaborative project involving high school students and their parents, as well as high school and university faculty members, for the purpose of contributing information to the scientific community while educating students about research processes and their own sleep/wake cycles and patterns. METHODS Sixty incoming high school seniors kept sleep/wake diaries beginning in August and continuing through 2 weeks after the start of school in September. Sleep diaries were also kept for 1 month in November and 1 month in February. Early-morning light treatments were given to 19 students in the last 2 weeks of November and the last 2 weeks of February. Neuropsychologic performance was measured with computer-administered tests. Paper-and-pencil tests were used for assessment of mood and vigor. A testing period consisted of 2 consecutive days at the beginning and end of November and at the beginning and end of February. Tests were given 3 times per day, ie, in the morning before school (6:30-8:00 AM), during midday lunch periods (11:30 AM to 1:00 PM), and in the afternoon (3:00-4:30 PM), on each of the test days. RESULTS Adolescents lost as much as 120 minutes of sleep per night during the week after the start of school, and weekend sleep time was also significantly longer (approximately 30 minutes) than that seen before the start of school (August). No significant differences were found between weekday sleep in the summer and weekend sleep during the school year. Early-morning light treatments did not modify total minutes of sleep per night, mood, or computer-administered vigilance test results. All students performed better in the afternoon than in the morning. Students in early morning classes reported being wearier, being less alert, and having to expend greater effort. CONCLUSIONS The results of this study demonstrated that current high school start times contribute to sleep deprivation among adolescents. Consistent with a delay in circadian sleep phase, students performed better later in the day than in the early morning. However, exposure to bright light in the morning did not change the sleep/wake cycle or improve daytime performance during weekdays. Both short-term and long-term strategies that address the epidemic of sleep deprivation among adolescents will be necessary to improve health and maximize school performance.
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Affiliation(s)
- Martha Hansen
- Science Department, Evanston Township High School, Evanston, Illinois, USA
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Boivin DB, James FO. Light treatment and circadian adaptation to shift work. INDUSTRIAL HEALTH 2005; 43:34-48. [PMID: 15732302 DOI: 10.2486/indhealth.43.34] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Work at unconventional hours can have both long and short term consequences. Shift workers are often required to perform their duties at times that are not favoured by the body's endogenous clock, or circadian pacemaker. A typical night shift worker, for example, may report reductions in alertness and performance during shifts, or significant difficulty attaining sleep of recuperative value in the day, all the while being more likely to develop health complications. The study of circadian physiology has significantly contributed to our current ability to aid the shift worker deal with atypical schedules. We discuss the usefulness of light treatment as a countermeasure for maladaptation to atypical work schedules.
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Affiliation(s)
- Diane B Boivin
- Center for Study and Treatment of Circadian Rhythms, Douglas Hospital Research Center, affiliated to the Department of Psychiatry, McGill University, 6875 LaSalle Boulevard, room F-1127, Montreal, Quebec, H4H 1R3, Canada
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Abstract
The controversy about potential health hazards associated with the exposure to electromagnetic fields (EMF) has been recently stimulated by the increasing use of mobile telecommunication devices. Attention has focused here on non-thermal effects of low-level high-frequency radiation, which does not lead to a heating of tissue. Scientific literature on the effects of high-frequency EMFs on sleep is reviewed. The epidemiological studies provide no evidence that sleep disturbances are a relevant complaint under exposure to such fields. Recent sleep laboratory studies have revealed a number of slight effects. Despite their heterogeneity, there seems to be some consistency regarding a slight sleep-promoting effect and an increase of the alpha power of the sleep EEG induced by high-frequency EMFs. However, for both the epidemiological and sleep laboratory studies, the database concerning sleep is up to now very limited. At the present level of knowledge, no final conclusions can be drawn from the available data concerning potential health hazards. Although there seem to be some biological effects, these do not provide evidence for any adverse health consequences. However, further research is needed for a better understanding of the interaction between EMFs and the sleep process.
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Affiliation(s)
- Klaus Mann
- Department of Psychiatry, University of Mainz, Untere Zahlbacher Str. 8, D-55101 Mainz, Germany.
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Siwak CT, Tapp PD, Zicker SC, Murphey HL, Muggenburg BA, Head E, Cotman CW, Milgram NW. Locomotor activity rhythms in dogs vary with age and cognitive status. Behav Neurosci 2003; 117:813-24. [PMID: 12931965 DOI: 10.1037/0735-7044.117.4.813] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Beagle dogs exhibited diurnal patterns of locomotor activity that varied as a function of age, cognitive status, and housing environment. Aged dogs housed in an indoor facility showed a delayed onset of activity following lights on and displayed shorter bouts of activity, with more rest periods during the day, compared with young dogs. Cognitively impaired aged dogs were more active and showed a delayed peak of activity compared with unimpaired aged dogs. Housing in continuous light did not disrupt activity rhythms. The effect of age was less prominent in dogs housed in an indoor/outdoor facility. This suggests that bright sunlight and natural light-dark transitions are better able to consolidate and synchronize the activity rhythms of the dogs.
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Affiliation(s)
- Christina T Siwak
- Institute of Medical Science, University of Toronto, Ontario, Canada
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