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Rabiei M, Masoumi SJ, Haghani M, Nematolahi S, Rabiei R, Mortazavi SMJ. Do blue light filter applications improve sleep outcomes? A study of smartphone users' sleep quality in an observational setting. Electromagn Biol Med 2024; 43:107-116. [PMID: 38461462 DOI: 10.1080/15368378.2024.2327432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 03/03/2024] [Indexed: 03/12/2024]
Abstract
Exposure to blue light at bedtime, suppresses melatonin secretion, postponing the sleep onset and interrupting the sleep process. Some smartphone manufacturers have introduced night-mode functions, which have been claimed to aid in improving sleep quality. In this study, we evaluate the impact of blue light filter application on decreasing blue light emissions and improving sleep quality. Participants in this study recorded the pattern of using their mobile phones through a questionnaire. In order to evaluate sleep quality, we used a PSQI questionnaire. Blue light filters were used by 9.7% of respondents, 9.7% occasionally, and 80% never. The mean score of PSQI was more than 5 in 54.10% of the participants and less than 5 in 45.90%. ANOVA test was performed to assess the relationship between using blue light filter applications and sleep quality (p-value = 0.925). The findings of this study indicate a connection between the use of blue light filter apps and habitual sleep efficiency in the 31-40 age group. However, our results align only to some extent with prior research, as we did not observe sustained positive effects on all parameters of sleep quality from the long-term use of blue light filtering apps. Several studies have found that blue light exposure can suppress melatonin secretion, exacerbating sleep problems. Some studies have reported that physical blue light filters, such as lenses, can affect melatonin secretion and improve sleep quality. However, the impact of blue light filtering applications remains unclear and debatable.
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Affiliation(s)
- Marziye Rabiei
- Student Research Committee, Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Science, Shiraz, Iran
| | - Seyed Jalil Masoumi
- Nutrition Research Center, School of Nutrition and Food Sciences, Shiraz University of Medical Science, Shiraz, Iran
- Gastroenterohepatology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Center for Cohort Study of SUMS Employees' Health, Shiraz University of Medical Science, Shiraz, Iran
| | - Masoud Haghani
- Department of Radiology, School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Samaneh Nematolahi
- Non-Communicable Diseases Research Center, Bam University of Medical Sciences, Bam, Iran
| | - Reza Rabiei
- Educational science expert, Department of Education, Bushehr, Iran
| | - Seyed Mohammad Javad Mortazavi
- Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Science, Shiraz, Iran
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Miller S, Cajochen C, Green A, Hanifin J, Huss A, Karipidis K, Loughran S, Oftedal G, O'Hagan J, Sliney DH, Croft R, van Rongen E, Cridland N, d'Inzeo G, Hirata A, Marino C, Röösli M, Watanabe S. ICNIRP Statement on Short Wavelength Light Exposure from Indoor Artificial Sources and Human Health. Health Phys 2024; 126:241-248. [PMID: 38381972 DOI: 10.1097/hp.0000000000001790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
ABSTRACT Concerns have been raised about the possibility of effects from exposure to short wavelength light (SWL), defined here as 380-550 nm, on human health. The spectral sensitivity of the human circadian timing system peaks at around 480 nm, much shorter than the peak sensitivity of daytime vision (i.e., 555 nm). Some experimental studies have demonstrated effects on the circadian timing system and on sleep from SWL exposure, especially when SWL exposure occurs in the evening or at night. The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has identified a lack of consensus among public health officials regarding whether SWL from artificial sources disrupts circadian rhythm, and if so, whether SWL-disrupted circadian rhythm is associated with adverse health outcomes. Systematic reviews of studies designed to examine the effects of SWL on sleep and human health have shown conflicting results. There are many variables that can affect the outcome of these experimental studies. One of the main problems in earlier studies was the use of photometric quantities as a surrogate for SWL exposure. Additionally, the measurement of ambient light may not be an accurate measure of the amount of light impinging on the intrinsically photosensitive retinal ganglion cells, which are now known to play a major role in the human circadian timing system. Furthermore, epidemiological studies of long-term effects of chronic SWL exposure per se on human health are lacking. ICNIRP recommends that an analysis of data gaps be performed to delineate the types of studies needed, the parameters that should be addressed, and the methodology that should be applied in future studies so that a decision about the need for exposure guidelines can be made. In the meantime, ICNIRP supports some recommendations for how the quality of future studies might be improved.
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Affiliation(s)
| | - Christian Cajochen
- ICNIRP SEG and Centre for Chronobiology at the University of Basel, Switzerland
| | - Adele Green
- ICNIRP SEG and QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - Anke Huss
- ICNIRP and Institute for Risk Assessment Sciences (IRAS) at Utrecht University, The Netherlands
| | - Ken Karipidis
- ICNIRP and Australian Radiation Protection and Nuclear Safety Authority (ARPANSA)
| | - Sarah Loughran
- ICNIRP SEG and Australian Radiation Protection and Nuclear Safety Authority (ARPANSA)
| | - Gunnhild Oftedal
- ICNIRP and Norwegian University of Science and Technology (NTNU)
| | - John O'Hagan
- ICNIRP SEG and Public Health England, United Kingdom
| | | | - Rodney Croft
- ICNIRP and Australian Centre for Electromagnetic Bioeffects Research, Illawarra Health & Medical Research Institute, University of Wollongong, Australia
| | | | | | | | | | - Carmela Marino
- ICNIRP and formerly Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Italy
| | - Martin Röösli
- ICNIRP and Swiss Tropical and Public Health Institute, Switzerland
| | - Soichi Watanabe
- ICNIRP and National Institute of Information and Communications Technology (NICT), Japan
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Hand AJ, Stone JE, Shen L, Vetter C, Cain SW, Bei B, Phillips AJK. Measuring light regularity: sleep regularity is associated with regularity of light exposure in adolescents. Sleep 2023; 46:zsad001. [PMID: 36625482 PMCID: PMC10424172 DOI: 10.1093/sleep/zsad001] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 10/30/2022] [Indexed: 01/11/2023] Open
Abstract
STUDY OBJECTIVES Light is the main time cue for the human circadian system. Sleep and light are intrinsically linked; light exposure patterns can influence sleep patterns and sleep can influence light exposure patterns. However, metrics for quantifying light regularity are lacking, and the relationship between sleep and light regularity is underexplored. We developed new metrics for light regularity and demonstrated their utility in adolescents, across school term and vacation. METHODS Daily sleep/wake and light patterns were measured using wrist actigraphy in 75 adolescents (54% male, 17.17 ± 0.83 years) over 2 weeks of school term and a subsequent 2-week vacation. The Sleep Regularity Index (SRI) and social jetlag were computed for each 2-week block. Light regularity was assessed using (1) variation in mean daily light timing (MLiT); (2) variation in daily photoperiod; and (3) the Light Regularity Index (LRI). Associations between SRI and each light regularity metric were examined, and within-individual changes in metrics were examined between school and vacation. RESULTS Higher SRI was significantly associated with more regular LRI scores during both school and vacation. There were no significant associations of SRI with variation in MLiT or daily photoperiod. Compared to school term, all three light regularity metrics were less variable during the vacation. CONCLUSIONS Light regularity is a multidimensional construct, which until now has not been formally defined. Irregular sleep patterns are associated with lower LRI, indicating that irregular sleepers also have irregular light inputs to the circadian system, which likely contributes to circadian disruption.
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Affiliation(s)
- Anthony J Hand
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia
| | - Julia E Stone
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia
| | - Lin Shen
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia
| | - Céline Vetter
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Sean W Cain
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia
| | - Bei Bei
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia
| | - Andrew J K Phillips
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash University, Clayton, VIC, Australia
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Dang L, Kanney ML, Hsu DP. The curious case of the Zzz's. J Clin Sleep Med 2023; 19:1009-1012. [PMID: 36740920 PMCID: PMC10152357 DOI: 10.5664/jcsm.10502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 12/21/2022] [Accepted: 01/13/2023] [Indexed: 02/07/2023]
Abstract
Excessive daytime sleepiness is a common presenting symptom that may present a diagnostic challenge for the sleep medicine clinician. We present a case of an adolescent female with excessive daytime sleepiness and "sleep attacks" who was evaluated using a 2-week sleep log, wrist actigraphy, baseline polysomnogram, and Multiple Sleep Latency Test. Multiple Sleep Latency Test results noted a short mean sleep latency without sleep onset rapid eye movement periods, concerning for possible central disorders of hypersomnolence. However, actigraphy data noted a habitual bedtime of midnight or later, resulting in less than recommended total sleep time for her age on weekdays with extended sleep periods on the weekends. The most unique actigraphy finding was exposure to ambient light throughout most overnight sleep periods. When actigraphy results were discussed with the patient, she revealed recent onset of severe anxiety with fear of sleeping in the dark. This case highlights the importance of thorough clinical evaluation, and careful interpretation of objective tests, when evaluating for causes of excessive daytime sleepiness. CITATION Dang L, Kanney ML, Hsu DP. The curious case of the Zzz's. J Clin Sleep Med. 2023;19(5):1009-1012.
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Affiliation(s)
- LeQuan Dang
- Department of Medicine, Baylor College of Medicine, Houston, Texas
- Pediatric Sleep Medicine, Texas Children’s Hospital, Houston, Texas
| | - Michelle L. Kanney
- Pediatric Sleep Medicine, Texas Children’s Hospital, Houston, Texas
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Daniel P. Hsu
- Pediatric Sleep Medicine, Texas Children’s Hospital, Houston, Texas
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
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Wang Y, Yang W, Zhang P, Ding Z, Wang L, Cheng J. Effects of light on the sleep-wakefulness cycle of mice mediated by intrinsically photosensitive retinal ganglion cells. Biochem Biophys Res Commun 2022; 592:93-98. [PMID: 35033872 DOI: 10.1016/j.bbrc.2022.01.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/02/2022] [Accepted: 01/08/2022] [Indexed: 11/21/2022]
Abstract
Intrinsically photosensitive retinal ganglion cells (ipRGCs) are able to synthesize the photosensitive protein melanopsin, which is involved in the regulation of circadian rhythms, the papillary light reflex and other nonimaging visual functions. To investigate whether ipRGCs are involved in mediating the light modulation of sleep-wakefulness in rodents, melanopsin knockout mice (MKO), melanopsin-only mice (MO) and coneless, rodless, melanopsin knockout mice (TKO) were used in this study to record electroencephalogram and electromyography variations in the normal 12:12 h light:dark cycle, and 1 h and 3 h light pulses were administered at 1 h after the light was turned off. In the normal 12:12 h light-dark cycle, the WT, MKO and MO mice had a regular day-night rhythm and no significant difference in wakefulness, rapid eye movement (REM) or nonrapid eye movement (NREM) sleep. However, TKO mice could not be entrained according to the light-dark cycle and exhibited a free-running rhythm. Extending the light pulse durations significantly changed the sleep and wakefulness activities of the WT and MO mice but did not have an effect on the MKO mice. These results indicate that melanopsin significantly affects REM and NREM sleep and that ipRGCs play an important role in light-induced sleep in mice.
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Affiliation(s)
- Yuan Wang
- Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China; Department of Physiology and Pathology, School of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, 230012, Anhui, China; Institute of Integrated Chinese and Western Medicine, Anhui Academy of Chinese Medicine, Hefei, 230012, China
| | - Wenzhi Yang
- Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Pingping Zhang
- Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Zhengxia Ding
- Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Liecheng Wang
- Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China.
| | - Juan Cheng
- Department of Physiology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China.
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Liset R, Grønli J, Henriksen RE, Henriksen TEG, Nilsen RM, Pallesen S. A randomized controlled trial on the effects of blue-blocking glasses compared to partial blue-blockers on sleep outcomes in the third trimester of pregnancy. PLoS One 2022; 17:e0262799. [PMID: 35089982 PMCID: PMC8797219 DOI: 10.1371/journal.pone.0262799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 12/15/2021] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE Sleep disturbances are common in pregnancy. Blocking blue light has been shown to improve sleep and may be a suitable intervention for sleep problems during pregnancy. The present study investigated the effects of blue light blocking in the evening and during nocturnal awakenings among pregnant women on primary sleep outcomes in terms of total sleep time, sleep efficiency and mid-point of sleep. METHODS In a double-blind randomized controlled trial, 60 healthy nulliparous pregnant women in the beginning of the third trimester were included. They were randomized, using a random number generator, either to a blue-blocking glass intervention (n = 30) or to a control glass condition constituting partial blue-blocking effect (n = 30). Baseline data were recorded for one week and outcomes were recorded in the last of two intervention/control weeks. Sleep was measured by actigraphy, sleep diaries, the Bergen Insomnia Scale, the Karolinska Sleepiness Scale and the Pre-Sleep Arousal Scale. RESULTS The results on the primary outcomes showed no significant mean difference between the groups at posttreatment, neither when assessed with sleep diary; total sleep time (difference = .78[min], 95%CI = -19.7, 21.3), midpoint of sleep (difference = -8.9[min], 95%CI = -23.7, 5.9), sleep efficiency (difference = -.06[%], 95%CI = -1.9, 1.8) and daytime functioning (difference = -.05[score points], 95%CI = -.33, .22), nor by actigraphy; total sleep time (difference = 13.0[min], 95%CI = -9.5, 35.5), midpoint of sleep (difference = 2.1[min], 95%CI = -11.6, 15.8) and sleep efficiency (difference = 1.7[%], 95%CI = -.4, 3.7). On the secondary outcomes, the Bergen Insomnia Scale, the Karolinska Sleepiness Scale and the Pre-Sleep Arousal Scale the blue-blocking glasses no statistically significant difference between the groups were found. Transient side-effects were reported in both groups (n = 3). CONCLUSIONS The use of blue-blocking glasses compared to partially blue-blocking glasses in a group of healthy pregnant participants did not show statistically significant effects on sleep outcomes. Research on the effects of blue-blocking glasses for pregnant women with sleep-problems or circadian disturbances is warranted. TRIAL REGISTRATION The trial is registered at ClinicalTrials.gov (NCT03114072).
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Affiliation(s)
- Randi Liset
- Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Bergen, Norway
| | - Janne Grønli
- Department of Biological and Medical Psychology, Faculty of Psychology, University of Bergen, Bergen, Norway
| | - Roger E. Henriksen
- Faculty of Health and Social Sciences, Western Norway University of Applied Sciences, Bergen, Norway
| | - Tone E. G. Henriksen
- Division of Mental Health Care, Fonna Local Health Authority, Valen Hospital, Valen, Norway
| | - Roy M. Nilsen
- Faculty of Health and Social Sciences, Western Norway University of Applied Sciences, Bergen, Norway
| | - Ståle Pallesen
- Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Bergen, Norway
- Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen, Norway
- Optentia, The Vaal Triangle Campus of The North-West University, Vanderbijlpark, South-Africa
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Zerbini G, Winnebeck EC, Merrow M. Weekly, seasonal, and chronotype-dependent variation of dim-light melatonin onset. J Pineal Res 2021; 70:e12723. [PMID: 33608951 DOI: 10.1111/jpi.12723] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/11/2021] [Accepted: 02/16/2021] [Indexed: 12/27/2022]
Abstract
In humans, the most important zeitgeber for entrainment is light. Laboratory studies have shown that meaningful changes in light exposure lead to phase shifts in markers of the circadian clock. In natural settings, light is a complex signal varying with external conditions and individual behaviors; nonetheless, phase of entrainment is assumed to be fairly stable. Here, we investigated the influence of season and weekly schedule (as indicators of variation in light landscapes) on phase of entrainment. Using a within-subjects design (N = 33), we assessed dim-light melatonin onset (DLMO) as a circadian phase marker in humans, on workdays and work-free days, in summer (under daylight saving time) and in winter, while also estimating sleep times from actimetry. Our mixed-model regressions show that both season and weekly structure are linked with changes in phase of entrainment and sleep. In summer, both DLMO and sleep times were about 1 hour earlier compared to winter, and sleep duration was shorter. On work-free days, DLMO and sleep times were later, and their phase relationship differed more relative to workdays. All these effects were stronger in later chronotypes (those who habitually sleep late). Our results confirm that phase of entrainment is earlier when stronger zeitgebers are present (summer) and show that it relates to midday or midnight rather than sunrise or sunset. Additionally, they suggest that late chronotypes are capable of rapid phase shifts each week as they move between workdays and work-free days, stimulating interesting questions about the stability of circadian phase under natural conditions.
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Affiliation(s)
- Giulia Zerbini
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Munich, Germany
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands
- Department of Medical Psychology and Sociology, Faculty of Medicine, University of Augsburg, Augsburg, Germany
| | - Eva C Winnebeck
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Martha Merrow
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Munich, Germany
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Stefani O, Freyburger M, Veitz S, Basishvili T, Meyer M, Weibel J, Kobayashi K, Shirakawa Y, Cajochen C. Changing color and intensity of LED lighting across the day impacts on circadian melatonin rhythms and sleep in healthy men. J Pineal Res 2021; 70:e12714. [PMID: 33378563 DOI: 10.1111/jpi.12714] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 01/09/2023]
Abstract
We examined whether dynamically changing light across a scheduled 16-h waking day influences sleepiness, cognitive performance, visual comfort, melatonin secretion, and sleep under controlled laboratory conditions in healthy men. Fourteen participants underwent a 49-h laboratory protocol in a repeated-measures study design. They spent the first 5 hours in the evening under standard lighting, followed by an 8-h nocturnal sleep episode at habitual bedtimes. Thereafter, volunteers either woke up to static light or to a dynamic light that changed spectrum and intensity across the scheduled 16-h waking day. Following an 8-h nocturnal sleep episode, the volunteers spent another 11 hours either under static or dynamic light. Static light attenuated the evening rise in melatonin levels more compared to dynamic light as indexed by a significant reduction in the melatonin AUC prior to bedtime during static light only. Participants felt less vigilant in the evening during dynamic light. After dynamic light, sleep latency was significantly shorter in both the baseline and treatment night while sleep structure, sleep quality, cognitive performance, and visual comfort did not significantly differ. The study shows that dynamic changes in spectrum and intensity of light promote melatonin secretion and sleep initiation in healthy men.
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Affiliation(s)
- Oliver Stefani
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
| | - Marlène Freyburger
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
| | - Simon Veitz
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
| | - Tamara Basishvili
- School of Natural Sciences and Medicine, Tengiz Oniani Laboratory of Sleep-Wakefulness Cycle Study, Ilia State University, Tbilisi, Georgia
| | - Martin Meyer
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
| | - Janine Weibel
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
| | - Kumpei Kobayashi
- Development and Engineering Department, Toshiba Materials Co. Ltd, Yokohama-City, Japan
| | - Yasuhiro Shirakawa
- Development and Engineering Department, Toshiba Materials Co. Ltd, Yokohama-City, Japan
| | - Christian Cajochen
- Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, Basel, Switzerland
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9
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Stebelova K, Roska J, Zeman M. Impact of Dim Light at Night on Urinary 6-Sulphatoxymelatonin Concentrations and Sleep in Healthy Humans. Int J Mol Sci 2020; 21:ijms21207736. [PMID: 33086713 PMCID: PMC7588991 DOI: 10.3390/ijms21207736] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/13/2020] [Accepted: 10/17/2020] [Indexed: 12/13/2022] Open
Abstract
Artificial light at night can have negative effects on human wellbeing and health. It can disrupt circadian rhythms, interfere with sleep, and participate in the progress of civilisation diseases. The aim of the present study was to explore if dim artificial light during the entire night (ALAN) can affect melatonin production and sleep quality in young volunteers. We performed two experiments in real-life home-based conditions. Young volunteers (n = 33) were exposed to four nights of one lux ALAN or two nights of five lux ALAN. Melatonin production, based on 6-sulphatoxymelatonin/creatinine concentrations in urine, and sleep quality, based on actimetry, were evaluated. Exposure to ALAN one lux during the entire night did not suppress aMT6s/creatinine concentrations but did aggravate sleep quality by increasing sleep fragmentation and one-minute immobility. ALAN up to five lux reduced melatonin biosynthesis significantly and interfered with sleep quality, as evidenced by an increased percentage of one-minute immobility and a tendency of increased fragmentation index. Our results show that people are more sensitive to low illuminance during the entire night, as previously expected. ALAN can interfere with melatonin production and sleep quality in young, healthy individuals, and both processes have different sensitivities to light.
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Affiliation(s)
- Katarina Stebelova
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 842 15 Bratislava, Slovak; (J.R.); (M.Z.)
- Correspondence:
| | - Jan Roska
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 842 15 Bratislava, Slovak; (J.R.); (M.Z.)
- Department of Genetics, Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, 845 05 Bratislava, Slovak
| | - Michal Zeman
- Department of Animal Physiology and Ethology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 842 15 Bratislava, Slovak; (J.R.); (M.Z.)
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10
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Stone JE, McGlashan EM, Quin N, Skinner K, Stephenson JJ, Cain SW, Phillips AJK. The Role of Light Sensitivity and Intrinsic Circadian Period in Predicting Individual Circadian Timing. J Biol Rhythms 2020; 35:628-640. [PMID: 33063595 DOI: 10.1177/0748730420962598] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
There is large interindividual variability in circadian timing, which is underestimated by mathematical models of the circadian clock. Interindividual differences in timing have traditionally been modeled by changing the intrinsic circadian period, but recent findings reveal an additional potential source of variability: large interindividual differences in light sensitivity. Using an established model of the human circadian clock with real-world light recordings, we investigated whether changes in light sensitivity parameters or intrinsic circadian period could capture variability in circadian timing between and within individuals. Healthy participants (n = 12, aged 18-26 years) underwent continuous light monitoring for 3 weeks (Actiwatch Spectrum). Salivary dim-light melatonin onset (DLMO) was measured each week. Using the recorded light patterns, a sensitivity analysis for predicted DLMO times was performed, varying 3 model parameters within physiological ranges: (1) a parameter determining the steepness of the dose-response curve to light (p), (2) a parameter determining the shape of the phase-response curve to light (K), and (3) the intrinsic circadian period (tau). These parameters were then fitted to obtain optimal predictions of the three DLMO times for each individual. The sensitivity analysis showed that the range of variation in the average predicted DLMO times across participants was 0.65 h for p, 4.28 h for K, and 3.26 h for tau. The default model predicted the DLMO times with a mean absolute error of 1.02 h, whereas fitting all 3 parameters reduced the mean absolute error to 0.28 h. Fitting the parameters independently, we found mean absolute errors of 0.83 h for p, 0.53 h for K, and 0.42 h for tau. Fitting p and K together reduced the mean absolute error to 0.44 h. Light sensitivity parameters captured similar variability in phase compared with intrinsic circadian period, indicating they are viable targets for individualizing circadian phase predictions. Future prospective work is needed that uses measures of light sensitivity to validate this approach.
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Affiliation(s)
- Julia E Stone
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Australia
| | - Elise M McGlashan
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Australia
| | - Nina Quin
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Australia
| | - Kayan Skinner
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Australia
| | - Jessica J Stephenson
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Australia
| | - Sean W Cain
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Australia
| | - Andrew J K Phillips
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Australia
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11
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Kim BG, Jeong KH, Shin HK. EVALUATION OF DOSE IN SLEEP BY MATTRESS CONTAINING MONAZITE. Radiat Prot Dosimetry 2019; 187:286-299. [PMID: 32415304 DOI: 10.1093/rpd/ncz163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/10/2019] [Accepted: 06/07/2019] [Indexed: 06/11/2023]
Abstract
Some companies in Korea have sold beds which contain a processed product containing monazite powder. Consumers may receive external exposure by radiation emitted by progeny radionuclides in uranium and thorium, and internal exposure through the breathing of radon progeny radionuclides produced in the decay chain. Thus, in this study, age specific dose conversion factors (mSv y-1 Bq-1) by external exposure and dose conversion factors by internal exposure (mSv y-1 per Bq m-3) were derived. Besides, a dose assessment program were developed to calculate dose by taking into account real conditions. And the age specific dose was evaluated using the radioactive concentration measured by the NSSC. As a results, external exposure was assessed to get effective doses in the range of 0.00086 to 0.0015 mSv y-1 by external exposure and a committed effective doses in the range of 1.3 to 12.26 mSv y-1 by internal exposure for all age groups.
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Affiliation(s)
- Bong-Gi Kim
- Nuclear and Radiation Safety Engineering, University of Science and Technology, Daejeon, Korea
| | - Kyu-Hwan Jeong
- Nuclear and Radiation Safety Engineering, University of Science and Technology, Daejeon, Korea
- Department of Radiation Safety, Korea Institute of Nuclear and Safety, Daejeon, Korea
| | - Hyeong-Ki Shin
- Department of Radiation Safety, Korea Institute of Nuclear and Safety, Daejeon, Korea
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12
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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13
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Bosquillon de Jenlis A, Del Vecchio F, Delanaud S, Gay-Queheillard J, Bach V, Pelletier A. Impacts of Subchronic, High-Level Noise Exposure on Sleep and Metabolic Parameters: A Juvenile Rodent Model. Environ Health Perspect 2019; 127:57004. [PMID: 31067133 PMCID: PMC6791575 DOI: 10.1289/ehp4045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 04/09/2019] [Accepted: 04/14/2019] [Indexed: 05/29/2023]
Abstract
BACKGROUND Noise is an environmental factor that has been associated with metabolic and sleep disorders. Sleep is a vital function, since it underpins physiologic processes and cognitive recovery and development. However, the effects of chronic noise exposure on the developing organism are still subject to debate. OBJECTIVE The objective of the present study was to assess the effects of subchronic, high-level noise exposure on sleep, apnea, and homeostasis in juvenile rats. METHODS Twenty-four 3-wk-old male Wistar rats were exposed to noise [[Formula: see text], [Formula: see text]] for 5 wk and 2 d during the 12-h rest period. Data on sleep stages, food and water intake, apnea, and body and organ weight were recorded. RESULTS Five weeks of high-level noise exposure were associated with hyperphagia ([Formula: see text]), body weight gain ([Formula: see text]), a heavier thymus ([Formula: see text]), and heavier adrenal glands ([Formula: see text]). A sleep analysis highlighted microstructural differences in the active period: in particular, the mean daily amount of rapid eye movement (REM) sleep as a proportion of total sleep time (TST) was higher. The mean daily amount of non-REM (NREM) sleep was lower in the exposed group, meaning that the intergroup difference in the TST was not significant. During a 1-h, noise-free plethysmographic recording during the rest period, the mean total amount of active wakefulness (AW) was lower in the exposed group (by 9.1 min), whereas the mean duration of an episode of REM sleep was higher (by 1.8 min), and the TST was higher (by 10.7 min). DISCUSSION Subchronic exposure of juvenile rats to high-intensity noise during the rest period was associated with some small but significant sleep disturbances, greater food and water intakes, greater body weight gain, and greater thymus and adrenal gland weights. The main effects of noise exposure on sleep were also observed in the 1-h plethysmography session after 5 wk of exposure. https://doi.org/10.1289/EHP4045.
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Affiliation(s)
- Aymar Bosquillon de Jenlis
- PériTox Laboratory, Périnatalité & Risques Toxiques, UMR-I 01 INERIS, Picardie Jules Verne University, Amiens, France
| | - Flavia Del Vecchio
- PériTox Laboratory, Périnatalité & Risques Toxiques, UMR-I 01 INERIS, Picardie Jules Verne University, Amiens, France
| | - Stéphane Delanaud
- PériTox Laboratory, Périnatalité & Risques Toxiques, UMR-I 01 INERIS, Picardie Jules Verne University, Amiens, France
| | - Jérôme Gay-Queheillard
- PériTox Laboratory, Périnatalité & Risques Toxiques, UMR-I 01 INERIS, Picardie Jules Verne University, Amiens, France
| | - Véronique Bach
- PériTox Laboratory, Périnatalité & Risques Toxiques, UMR-I 01 INERIS, Picardie Jules Verne University, Amiens, France
| | - Amandine Pelletier
- PériTox Laboratory, Périnatalité & Risques Toxiques, UMR-I 01 INERIS, Picardie Jules Verne University, Amiens, France
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14
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Pilz LK, Levandovski R, Oliveira MAB, Hidalgo MP, Roenneberg T. Sleep and light exposure across different levels of urbanisation in Brazilian communities. Sci Rep 2018; 8:11389. [PMID: 30061685 PMCID: PMC6065379 DOI: 10.1038/s41598-018-29494-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 06/26/2018] [Indexed: 12/22/2022] Open
Abstract
Quilombos are settlements originally founded by Africans and African descendants (Quilombolas) in remote parts of Brazil to escape slavery. Due to individual histories, Quilombos nowadays exhibit different states of industrialisation, making them ideal for studying the influence of electrification on daily behaviour. In a comparative approach, we aimed to understand whether and how human sleep changes with the introduction of artificial light. We investigated daily rest-activity-rhythms and sleep-patterns in the Quilombolas' by both wrist actimetry and the Munich ChronoType Questionnaire (MCTQ; the results of these two instruments correlated highly). Seven communities (MCTQ: N = 213/actimetry: N = 125) were compared in this study. Light exposure, phase of activity, sleep timing and duration differ across communities with various levels of urbanisation and histories of access to electricity. People living without electricity and those, who acquired it only very recently on average sleep earlier than those in more urbanised communities (mid-sleep about 1 hour earlier); sleep duration tends to be longer. Our results and those of others show that use of electricity and modern lifestyles have changed sleep behaviour. To understand the consequences of these changes for health, further studies are warranted.
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Affiliation(s)
- Luísa K Pilz
- Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre (HCPA)/Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
- Programa de Pós-Graduação em Psiquiatria e Ciências do Comportamento, Faculdade de Medicina - UFRGS, Porto Alegre, RS, Brazil
| | - Rosa Levandovski
- Programa de Pós-Graduação em Avaliação e Produção de Tecnologias para o SUS - GHC, Porto Alegre, RS, Brazil
- Programa de Pós-Graduação em Saúde Coletiva - UFRGS, Porto Alegre, RS, Brazil
| | - Melissa A B Oliveira
- Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre (HCPA)/Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
- Programa de Pós-Graduação em Psiquiatria e Ciências do Comportamento, Faculdade de Medicina - UFRGS, Porto Alegre, RS, Brazil
| | - Maria Paz Hidalgo
- Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre (HCPA)/Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
- Programa de Pós-Graduação em Psiquiatria e Ciências do Comportamento, Faculdade de Medicina - UFRGS, Porto Alegre, RS, Brazil
| | - Till Roenneberg
- Institute of Medical Psychology, LMU, Munich, BY, Germany.
- Visiting Professor at UFRGS/CAPES, Porto Alegre, RS, Brazil.
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15
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Lunn RM, Blask DE, Coogan AN, Figueiro MG, Gorman MR, Hall JE, Hansen J, Nelson RJ, Panda S, Smolensky MH, Stevens RG, Turek FW, Vermeulen R, Carreón T, Caruso CC, Lawson CC, Thayer KA, Twery MJ, Ewens AD, Garner SC, Schwingl PJ, Boyd WA. Health consequences of electric lighting practices in the modern world: A report on the National Toxicology Program's workshop on shift work at night, artificial light at night, and circadian disruption. Sci Total Environ 2017; 607-608:1073-1084. [PMID: 28724246 PMCID: PMC5587396 DOI: 10.1016/j.scitotenv.2017.07.056] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/07/2017] [Accepted: 07/07/2017] [Indexed: 05/24/2023]
Abstract
The invention of electric light has facilitated a society in which people work, sleep, eat, and play at all hours of the 24-hour day. Although electric light clearly has benefited humankind, exposures to electric light, especially light at night (LAN), may disrupt sleep and biological processes controlled by endogenous circadian clocks, potentially resulting in adverse health outcomes. Many of the studies evaluating adverse health effects have been conducted among night- and rotating-shift workers, because this scenario gives rise to significant exposure to LAN. Because of the complexity of this topic, the National Toxicology Program convened an expert panel at a public workshop entitled "Shift Work at Night, Artificial Light at Night, and Circadian Disruption" to obtain input on conducting literature-based health hazard assessments and to identify data gaps and research needs. The Panel suggested describing light both as a direct effector of endogenous circadian clocks and rhythms and as an enabler of additional activities or behaviors that may lead to circadian disruption, such as night-shift work and atypical and inconsistent sleep-wake patterns that can lead to social jet lag. Future studies should more comprehensively characterize and measure the relevant light-related exposures and link these exposures to both time-independent biomarkers of circadian disruption and biomarkers of adverse health outcomes. This information should lead to improvements in human epidemiological and animal or in vitro models, more rigorous health hazard assessments, and intervention strategies to minimize the occurrence of adverse health outcomes due to these exposures.
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Affiliation(s)
- Ruth M Lunn
- Office of the Report on Carcinogens, Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC, United States
| | - David E Blask
- Department of Structural and Cellular Biology, Laboratory of Chrono-Neuroendocrine Oncology, Tulane University School of Medicine, New Orleans, LA, United States
| | - Andrew N Coogan
- Maynooth University Department of Psychology, National University of Ireland, Maynooth, County Kildare, Ireland
| | - Mariana G Figueiro
- Light and Health Program, Lighting Research Center, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Michael R Gorman
- Department of Psychology and Center for Circadian Biology, University of California, San Diego, CA, United States
| | - Janet E Hall
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
| | - Johnni Hansen
- Danish Cancer Society Research Centre, Copenhagen, Denmark
| | - Randy J Nelson
- Department of Neuroscience, Neuroscience Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | | | - Michael H Smolensky
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, United States; Sleep Medicine, The University of Texas-Houston McGovern School of Medicine, Houston, TX, United States
| | - Richard G Stevens
- School of Medicine, University of Connecticut, Farmington, CT, United States
| | - Fred W Turek
- Center for Sleep & Circadian Biology, Northwestern University, Evanston, IL, United States
| | - Roel Vermeulen
- Division of Environmental Epidemiology, Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands
| | - Tania Carreón
- National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention, Cincinnati, OH, United States
| | - Claire C Caruso
- National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention, Cincinnati, OH, United States
| | - Christina C Lawson
- National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention, Cincinnati, OH, United States
| | - Kristina A Thayer
- Office of Health Assessment and Translation, Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC, United States
| | - Michael J Twery
- National Center on Sleep Disorders Research, Division of Lung Diseases, National Heart, Lung, and Blood Institute (NHLBI), Bethesda, MD, United States
| | - Andrew D Ewens
- Contractor in support of the NIEHS Report on Carcinogens, Integrated Laboratory Systems (ILS), Durham, NC, United States
| | - Sanford C Garner
- Contractor in support of the NIEHS Report on Carcinogens, Integrated Laboratory Systems (ILS), Durham, NC, United States
| | - Pamela J Schwingl
- Contractor in support of the NIEHS Report on Carcinogens, Integrated Laboratory Systems (ILS), Durham, NC, United States
| | - Windy A Boyd
- Office of Health Assessment and Translation, Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC, United States.
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16
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Ouyang JQ, de Jong M, van Grunsven RHA, Matson KD, Haussmann MF, Meerlo P, Visser ME, Spoelstra K. Restless roosts: Light pollution affects behavior, sleep, and physiology in a free-living songbird. Glob Chang Biol 2017; 23:4987-4994. [PMID: 28597541 DOI: 10.1111/gcb.13756] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 04/30/2017] [Indexed: 06/07/2023]
Abstract
The natural nighttime environment is increasingly polluted by artificial light. Several studies have linked artificial light at night to negative impacts on human health. In free-living animals, light pollution is associated with changes in circadian, reproductive, and social behavior, but whether these animals also suffer from physiologic costs remains unknown. To fill this gap, we made use of a unique network of field sites which are either completely unlit (control), or are artificially illuminated with white, green, or red light. We monitored nighttime activity of adult great tits, Parus major, and related this activity to within-individual changes in physiologic indices. Because altered nighttime activity as a result of light pollution may affect health and well-being, we measured oxalic acid concentrations as a biomarker for sleep restriction, acute phase protein concentrations and malaria infection as indices of immune function, and telomere lengths as an overall measure of metabolic costs. Compared to other treatments, individuals roosting in the white light were much more active at night. In these individuals, oxalic acid decreased over the course of the study. We also found that individuals roosting in the white light treatment had a higher probability of malaria infection. Our results indicate that white light at night increases nighttime activity levels and sleep debt and affects disease dynamics in a free-living songbird. Our study offers the first evidence of detrimental effects of light pollution on the health of free-ranging wild animals.
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Affiliation(s)
- Jenny Q Ouyang
- Department of Biology, University of Nevada, Reno, Reno, NV, USA
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Maaike de Jong
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Roy H A van Grunsven
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
- Plant Ecology and Nature Conservation Group, Wageningen University, Wageningen, The Netherlands
| | - Kevin D Matson
- Resource Ecology Group, Wageningen University, Wageningen, The Netherlands
| | | | - Peter Meerlo
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Kamiel Spoelstra
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
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17
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St Hilaire MA, Rüger M, Fratelli F, Hull JT, Phillips AJK, Lockley SW. Modeling Neurocognitive Decline and Recovery During Repeated Cycles of Extended Sleep and Chronic Sleep Deficiency. Sleep 2017; 40:2660406. [PMID: 28364449 PMCID: PMC6084743 DOI: 10.1093/sleep/zsw009] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2016] [Indexed: 11/13/2022] Open
Abstract
Study Objectives Intraindividual night-to-night sleep duration is often insufficient and variable. Here we report the effects of such chronic variable sleep deficiency on neurobehavioral performance and the ability of state-of-the-art models to predict these changes. Methods Eight healthy males (mean age ± SD: 23.9 ± 2.4 years) studied at our inpatient intensive physiologic monitoring unit completed an 11-day protocol with a baseline 10-hour sleep opportunity and three cycles of two 3-hour time-in-bed (TIB) and one 10-hour TIB sleep opportunities. Participants received one of three polychromatic white light interventions (200 lux 4100K, 200 or 400 lux 17000K) for 3.5 hours on the morning following the second 3-hour TIB opportunity each cycle. Neurocognitive performance was assessed using the psychomotor vigilance test (PVT) administered every 1-2 hours. PVT data were compared to predictions of five group-average mathematical models that incorporate chronic sleep loss functions. Results While PVT performance deteriorated cumulatively following each cycle of two 3-hour sleep opportunities, and improved following each 10-hour sleep opportunity, performance declined cumulatively throughout the protocol at a more accelerated rate than predicted by state-of-the-art group-average mathematical models. Subjective sleepiness did not reflect performance. The light interventions had minimal effect. Conclusions Despite apparent recovery following each extended sleep opportunity, residual performance impairment remained and deteriorated rapidly when rechallenged with subsequent sleep loss. None of the group-average models were capable of predicting both the build-up in impairment and recovery profile of performance observed at the group or individual level, raising concerns regarding their use in real-world settings to predict performance and improve safety.
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Affiliation(s)
- Melissa A St Hilaire
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA
- Department of Medicine, Division of Sleep Medicine, Harvard Medical School, Boston, MA
| | - Melanie Rüger
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA
- Department of Medicine, Division of Sleep Medicine, Harvard Medical School, Boston, MA
| | - Federico Fratelli
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA
- Department of Medicine, Division of Sleep Medicine, Harvard Medical School, Boston, MA
- Department of Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Joseph T Hull
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA
- Department of Medicine, Division of Sleep Medicine, Harvard Medical School, Boston, MA
| | - Andrew J K Phillips
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA
- Department of Medicine, Division of Sleep Medicine, Harvard Medical School, Boston, MA
| | - Steven W Lockley
- Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital, Boston, MA
- Department of Medicine, Division of Sleep Medicine, Harvard Medical School, Boston, MA
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18
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Kovács KA, O’Neill J, Schoenenberger P, Penttonen M, Ranguel Guerrero DK, Csicsvari J. Optogenetically Blocking Sharp Wave Ripple Events in Sleep Does Not Interfere with the Formation of Stable Spatial Representation in the CA1 Area of the Hippocampus. PLoS One 2016; 11:e0164675. [PMID: 27760158 PMCID: PMC5070819 DOI: 10.1371/journal.pone.0164675] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 09/28/2016] [Indexed: 11/18/2022] Open
Abstract
During hippocampal sharp wave/ripple (SWR) events, previously occurring, sensory input-driven neuronal firing patterns are replayed. Such replay is thought to be important for plasticity-related processes and consolidation of memory traces. It has previously been shown that the electrical stimulation-induced disruption of SWR events interferes with learning in rodents in different experimental paradigms. On the other hand, the cognitive map theory posits that the plastic changes of the firing of hippocampal place cells constitute the electrophysiological counterpart of the spatial learning, observable at the behavioral level. Therefore, we tested whether intact SWR events occurring during the sleep/rest session after the first exploration of a novel environment are needed for the stabilization of the CA1 code, which process requires plasticity. We found that the newly-formed representation in the CA1 has the same level of stability with optogenetic SWR blockade as with a control manipulation that delivered the same amount of light into the brain. Therefore our results suggest that at least in the case of passive exploratory behavior, SWR-related plasticity is dispensable for the stability of CA1 ensembles.
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Affiliation(s)
- Krisztián A. Kovács
- Institute of Science and Technology Austria, Klosterneuburg, Austria
- * E-mail: (JC); (KAK)
| | - Joseph O’Neill
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | | | - Markku Penttonen
- Department of Psychology, University of Jyvaskyla, Jyvaskyla, Finland
| | | | - Jozsef Csicsvari
- Institute of Science and Technology Austria, Klosterneuburg, Austria
- * E-mail: (JC); (KAK)
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19
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Cho CH, Moon JH, Yoon HK, Kang SG, Geum D, Son GH, Lim JM, Kim L, Lee EI, Lee HJ. Molecular circadian rhythm shift due to bright light exposure before bedtime is related to subthreshold bipolarity. Sci Rep 2016; 6:31846. [PMID: 27545669 PMCID: PMC4992827 DOI: 10.1038/srep31846] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/27/2016] [Indexed: 12/18/2022] Open
Abstract
This study examined the link between circadian rhythm changes due to bright light exposure and subthreshold bipolarity. Molecular circadian rhythms, polysomnography, and actigraphy data were studied in 25 young, healthy male subjects, divided into high and low mood disorder questionnaire (MDQ) score groups. During the first 2 days of the study, the subjects were exposed to daily-living light (150 lux) for 4 hours before bedtime. Saliva and buccal cells were collected 5 times a day for 2 consecutive days. During the subsequent 5 days, the subjects were exposed to bright light (1,000 lux), and saliva and buccal cell samples were collected in the same way. Molecular circadian rhythms were analyzed using sine regression. Circadian rhythms of cortisol (F = 16.956, p < 0.001) and relative PER1/ARNTL gene expression (F = 122.1, p < 0.001) showed a delayed acrophase in both groups after bright light exposure. The high MDQ score group showed a significant delay in acrophase compared to the low MDQ score group only in salivary cortisol (F = 8.528, p = 0.008). The high MDQ score group showed hypersensitivity in cortisol rhythm shift after bright light exposure, suggesting characteristic molecular circadian rhythm changes in the high MDQ score group may be related to biological processes downstream from core circadian clock gene expression.
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Affiliation(s)
- Chul-Hyun Cho
- Department of Psychiatry, Korea University College of Medicine, Seoul, South Korea
- Sleep-Wake Disorders Center, Korea University Anam Hospital, Seoul, South Korea
| | - Joung-Ho Moon
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Ho-Kyoung Yoon
- Department of Psychiatry, Korea University College of Medicine, Seoul, South Korea
- Sleep-Wake Disorders Center, Korea University Anam Hospital, Seoul, South Korea
| | - Seung-Gul Kang
- Department of Psychiatry, Gachon University School of Medicine, Incheon, South Korea
| | - Dongho Geum
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
| | - Gi-Hoon Son
- Department of Legal Medicine, Korea University College of Medicine, Seoul, South Korea
| | - Jong-Min Lim
- Department of Lighting Environment Research, Korea Institute of Lighting Technology, Seoul, South Korea
| | - Leen Kim
- Department of Psychiatry, Korea University College of Medicine, Seoul, South Korea
- Sleep-Wake Disorders Center, Korea University Anam Hospital, Seoul, South Korea
| | - Eun-Il Lee
- Department of Preventive Medicine, Korea University College of Medicine, Seoul, South Korea
| | - Heon-Jeong Lee
- Department of Psychiatry, Korea University College of Medicine, Seoul, South Korea
- Sleep-Wake Disorders Center, Korea University Anam Hospital, Seoul, South Korea
- Department of Biomedical Science, Korea University College of Medicine, Seoul, South Korea
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20
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Abstract
In mammals, light exerts pervasive effects on physiology and behavior in two ways: indirectly through clock synchronization and the phase adjustment of circadian rhythms, and directly through the promotion of alertness and sleep, respectively, in diurnal and nocturnal species. A recent report by Pilorz and colleagues describes an even more complex role for the acute effects of light. In mice, blue light acutely causes behavioral arousal, whereas green wavelengths promote sleep. These opposing effects are mediated by melanopsin-based phototransduction through different neural pathways. These findings reconcile nocturnal and diurnal species through a common alerting response to blue light. One can hypothesize that the opposite responses to natural polychromatic light in night- or day-active animals may reflect higher sensitivity of nocturnal species to green, and diurnals to blue wavelengths, resulting in hypnogenic and alerting effects, respectively. Additional questions remain to be clarified. How do different light wavelengths affect other behaviors such as mood and cognition? How do those results apply to humans? How does light pose either a risk or benefit, depending on whether one needs to be asleep or alert? Indeed, in addition to timing, luminance levels, and light exposure duration, these findings stress the need to understand how best to adapt the color spectrum of light to our needs and to take this into account for the design of daily lighting concepts—a key challenge for today’s society, especially with the emergence of LED light technology.
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Affiliation(s)
- Patrice Bourgin
- CNRS-UPR 3212, Institute of Cellular and Integrative Neurosciences, Sleep Disorders Center—CIRCSom, CHU and FMTS, University of Strasbourg, Strasbourg, France
- * E-mail:
| | - Jeffrey Hubbard
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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Pilorz V, Tam SKE, Hughes S, Pothecary CA, Jagannath A, Hankins MW, Bannerman DM, Lightman SL, Vyazovskiy VV, Nolan PM, Foster RG, Peirson SN. Melanopsin Regulates Both Sleep-Promoting and Arousal-Promoting Responses to Light. PLoS Biol 2016; 14:e1002482. [PMID: 27276063 PMCID: PMC4898879 DOI: 10.1371/journal.pbio.1002482] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 05/13/2016] [Indexed: 11/30/2022] Open
Abstract
Light plays a critical role in the regulation of numerous aspects of physiology and behaviour, including the entrainment of circadian rhythms and the regulation of sleep. These responses involve melanopsin (OPN4)-expressing photosensitive retinal ganglion cells (pRGCs) in addition to rods and cones. Nocturnal light exposure in rodents has been shown to result in rapid sleep induction, in which melanopsin plays a key role. However, studies have also shown that light exposure can result in elevated corticosterone, a response that is not compatible with sleep. To investigate these contradictory findings and to dissect the relative contribution of pRGCs and rods/cones, we assessed the effects of light of different wavelengths on behaviourally defined sleep. Here, we show that blue light (470 nm) causes behavioural arousal, elevating corticosterone and delaying sleep onset. By contrast, green light (530 nm) produces rapid sleep induction. Compared to wildtype mice, these responses are altered in melanopsin-deficient mice (Opn4-/-), resulting in enhanced sleep in response to blue light but delayed sleep induction in response to green or white light. We go on to show that blue light evokes higher Fos induction in the SCN compared to the sleep-promoting ventrolateral preoptic area (VLPO), whereas green light produced greater responses in the VLPO. Collectively, our data demonstrates that nocturnal light exposure can have either an arousal- or sleep-promoting effect, and that these responses are melanopsin-mediated via different neural pathways with different spectral sensitivities. These findings raise important questions relating to how artificial light may alter behaviour in both the work and domestic setting. Light can produce either sleep or arousal in mice. This study reveals that these opposing effects depend upon the wavelength of light and appear to involve separate pathways, both modulated by the photopigment melanopsin. Light exerts profound effects on our physiology and behaviour, setting our biological clocks to the correct time and regulating when we are asleep and we are awake. The photoreceptors mediating these responses include the rods and cones involved in vision, as well as a subset of photosensitive retinal ganglion cells (pRGCs) expressing the blue light-sensitive photopigment melanopsin. Previous studies have shown that mice lacking melanopsin show impaired sleep in response to light. However, other studies have shown that light increases glucocorticoid release—a response typically associated with stress. To address these contradictory findings, we studied the responses of mice to light of different colours. We found that blue light was aversive, delaying sleep onset and increasing glucocorticoid levels. By contrast, green light led to rapid sleep onset. These different behavioural effects appear to be driven by different neural pathways. Surprisingly, both responses were impaired in mice lacking melanopsin. These data show that light can promote either sleep or arousal. Moreover, they provide the first evidence that melanopsin directly mediates the effects of light on glucocorticoids. This work shows the extent to which light affects our physiology and has important implications for the design and use of artificial light sources.
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Affiliation(s)
- Violetta Pilorz
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Shu K. E. Tam
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Steven Hughes
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Carina A. Pothecary
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Aarti Jagannath
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Mark W. Hankins
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - David M. Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Stafford L. Lightman
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, United Kingdom
| | - Vladyslav V. Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Patrick M. Nolan
- MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, United Kingdom
| | - Russell G. Foster
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail: (SNP); (RGF)
| | - Stuart N. Peirson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail: (SNP); (RGF)
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Danker-Hopfe H, Dorn H, Bolz T, Peter A, Hansen ML, Eggert T, Sauter C. Effects of mobile phone exposure (GSM 900 and WCDMA/UMTS) on polysomnography based sleep quality: An intra- and inter-individual perspective. Environ Res 2016; 145:50-60. [PMID: 26618505 DOI: 10.1016/j.envres.2015.11.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 11/10/2015] [Accepted: 11/11/2015] [Indexed: 05/21/2023]
Abstract
BACKGROUND Studies on effects of radio frequency-electromagnetic fields (RF-EMF) on the macrostructure of sleep so far yielded inconsistent results. This study investigated whether possible effects of RF-EMF exposure differ between individuals. OBJECTIVE In a double-blind, randomized, sham-controlled cross-over study possible effects of electromagnetic fields emitted by pulsed Global System for Mobile Communications (GSM) 900 and Wideband Code-Division Multiple Access (WCDMA)/Universal Mobile Telecommunications System (WCDMA/UMTS) devices on sleep were analysed. METHODS Thirty healthy young men (range 18-30 years) were exposed three times per exposure condition while their sleep was recorded. Sleep was evaluated according to the American Academy of Sleep Medicine standard and eight basic sleep variables were considered. RESULTS Data analyses at the individual level indicate that RF-EMF effects are observed in 90% of the individuals and that all sleep variables are affected in at least four subjects. While sleep of participants was affected in various numbers, combinations of sleep variables and in different directions, showing improvements but also deteriorations, the only consistent finding was an increase of stage R sleep under GSM 900MHz exposure (9 of 30 subjects) as well as under WCDMA/UMTS exposure (10 of 30 subjects). CONCLUSIONS The results underline that sleep of individuals can be affected differently. The observations found here may indicate an underlying thermal mechanism of RF-EMF on human REM sleep. Nevertheless, the effect of an increase in stage R sleep in one third of the individuals does not necessarily indicate a disturbance of sleep.
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Affiliation(s)
- Heidi Danker-Hopfe
- Competence Center of Sleep Medicine and Sleep Research, Department of Psychiatry and Psychotherapy, Charité - Universitaetsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany.
| | - Hans Dorn
- Competence Center of Sleep Medicine and Sleep Research, Department of Psychiatry and Psychotherapy, Charité - Universitaetsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany.
| | - Thomas Bolz
- Institute of Mobile and Satellite communication Technology GmbH, Carl-Friedrich-Gauß-Straße 2, 47475 Kamp-Lintfort, Germany.
| | - Anita Peter
- Competence Center of Sleep Medicine and Sleep Research, Department of Psychiatry and Psychotherapy, Charité - Universitaetsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany.
| | - Marie-Luise Hansen
- Competence Center of Sleep Medicine and Sleep Research, Department of Psychiatry and Psychotherapy, Charité - Universitaetsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany.
| | - Torsten Eggert
- Competence Center of Sleep Medicine and Sleep Research, Department of Psychiatry and Psychotherapy, Charité - Universitaetsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany.
| | - Cornelia Sauter
- Competence Center of Sleep Medicine and Sleep Research, Department of Psychiatry and Psychotherapy, Charité - Universitaetsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany.
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Muindi F, Colas D, Ikeme J, Ruby NF, Heller HC. Loss of Melanopsin Photoreception and Antagonism of the Histamine H3 Receptor by Ciproxifan Inhibit Light-Induced Sleep in Mice. PLoS One 2015; 10:e0128175. [PMID: 26083020 PMCID: PMC4471207 DOI: 10.1371/journal.pone.0128175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/24/2015] [Indexed: 12/17/2022] Open
Abstract
Light has direct effects on sleep and wakefulness causing arousal in diurnal animals and sleep in nocturnal animals. In the present study, we assessed the modulation of light-induced sleep by melanopsin and the histaminergic system by exposing mice to millisecond light flashes and continuous light respectively. First, we show that the induction of sleep by millisecond light flashes is dose dependent as a function of light flash number. We found that exposure to 60 flashes of light occurring once every 60 seconds for 1-h (120-ms of total light over an hour) induced a similar amount of sleep as a continuous bright light pulse. Secondly, the induction of sleep by millisecond light flashes was attenuated in the absence of melanopsin when animals were presented with flashes occurring every 60 seconds over a 3-h period beginning at ZT13. Lastly, the acute administration of a histamine H3 autoreceptor antagonist, ciproxifan, blocked the induction of sleep by a 1-h continuous light pulse during the dark period. Ciproxifan caused a decrease in NREMS delta power and an increase in theta activity during both sleep and wake periods respectively. The data suggest that some form of temporal integration occurs in response to millisecond light flashes, and that this process requires melanopsin photoreception. Furthermore, the pharmacological data suggest that the increase of histaminergic neurotransmission is sufficient to attenuate the light-induced sleep response during the dark period.
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Affiliation(s)
- Fanuel Muindi
- Department of Biology, Stanford University, Stanford, California, United States of America
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
| | - Damien Colas
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Jesse Ikeme
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Norman F. Ruby
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - H. Craig Heller
- Department of Biology, Stanford University, Stanford, California, United States of America
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Pelletier A, Delanaud S, Décima P, Thuroczy G, de Seze R, Cerri M, Bach V, Libert JP, Loos N. Effects of chronic exposure to radiofrequency electromagnetic fields on energy balance in developing rats. Environ Sci Pollut Res Int 2013; 20:2735-46. [PMID: 23143821 DOI: 10.1007/s11356-012-1266-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 10/16/2012] [Indexed: 05/16/2023]
Abstract
The effects of radiofrequency electromagnetic fields (RF-EMF) on the control of body energy balance in developing organisms have not been studied, despite the involvement of energy status in vital physiological functions. We examined the effects of chronic RF-EMF exposure (900 MHz, 1 V m(-1)) on the main functions involved in body energy homeostasis (feeding behaviour, sleep and thermoregulatory processes). Thirteen juvenile male Wistar rats were exposed to continuous RF-EMF for 5 weeks at 24 °C of air temperature (T a) and compared with 11 non-exposed animals. Hence, at the beginning of the 6th week of exposure, the functions were recorded at T a of 24 °C and then at 31 °C. We showed that the frequency of rapid eye movement sleep episodes was greater in the RF-EMF-exposed group, independently of T a (+42.1 % at 24 °C and +31.6 % at 31 °C). The other effects of RF-EMF exposure on several sleep parameters were dependent on T a. At 31 °C, RF-EMF-exposed animals had a significantly lower subcutaneous tail temperature (-1.21 °C) than controls at all sleep stages; this suggested peripheral vasoconstriction, which was confirmed in an experiment with the vasodilatator prazosin. Exposure to RF-EMF also increased daytime food intake (+0.22 g h(-1)). Most of the observed effects of RF-EMF exposure were dependent on T a. Exposure to RF-EMF appears to modify the functioning of vasomotor tone by acting peripherally through α-adrenoceptors. The elicited vasoconstriction may restrict body cooling, whereas energy intake increases. Our results show that RF-EMF exposure can induce energy-saving processes without strongly disturbing the overall sleep pattern.
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Affiliation(s)
- Amandine Pelletier
- PériTox Laboratory (EA 4285-UMI01), Faculty of Medicine, Jules Verne University of Picardy, 3 rue des Louvels, CS 13602, 80036, Amiens cedex 1, France
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25
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Zhu Y, Fu A, Hoffman AE, Figueiro MG, Carskadon MA, Sharkey KM, Rea MS. Advanced sleep schedules affect circadian gene expression in young adults with delayed sleep schedules. Sleep Med 2013; 14:449-55. [PMID: 23562184 DOI: 10.1016/j.sleep.2012.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 11/30/2012] [Accepted: 12/17/2012] [Indexed: 01/09/2023]
Abstract
BACKGROUND Human circadian rhythms are regulated by the interplay between circadian genes and environmental stimuli. The influence of altered sleep-wake schedules or light on human circadian gene expression patterns is not well characterized. METHODS Twenty-one young adults were asked to keep to their usual sleep schedules and two blood samples were drawn at the end of the first week from each subject based on estimated time of dim light melatonin onset (DLMO); the first sample was obtained one and a half hours before the estimated DLMO and the second three hours later, at one and a half hours after the estimated DLMO. During the second week, participants were randomized into two groups, one that received a one hour blue-light (λmax=470 nm) exposure in the morning and one that received a comparable morning dim-light exposure. Two blood samples were obtained at the same clock times as the previous week at the end of the second week. RESULTS We measured the expression of 10 circadian genes in response to sleep-wake schedule advancement and morning blue-light stimulation in the peripheral blood of 21 participants during a two-week field study. We found that nine of the 10 circadian genes showed significant expression changes from the first to the second week for participants in both the blue-light and dim-light groups, likely reflecting significant advances in circadian phase. CONCLUSIONS This wholesale change in circadian gene expression may reflect considerable advances in circadian phase (i.e., advance in DLMO) from the first to the second week resulting from the advanced, daily personal light exposures.
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Affiliation(s)
- Yong Zhu
- School of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT, USA.
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26
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Wood B, Rea MS, Plitnick B, Figueiro MG. Light level and duration of exposure determine the impact of self-luminous tablets on melatonin suppression. Appl Ergon 2013; 44:237-240. [PMID: 22850476 DOI: 10.1016/j.apergo.2012.07.008] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 07/10/2012] [Accepted: 07/12/2012] [Indexed: 06/01/2023]
Abstract
Exposure to light from self-luminous displays may be linked to increased risk for sleep disorders because these devices emit optical radiation at short wavelengths, close to the peak sensitivity of melatonin suppression. Thirteen participants experienced three experimental conditions in a within-subjects design to investigate the impact of self-luminous tablet displays on nocturnal melatonin suppression: 1) tablets-only set to the highest brightness, 2) tablets viewed through clear-lens goggles equipped with blue light-emitting diodes that provided 40 lux of 470-nm light at the cornea, and 3) tablets viewed through orange-tinted glasses (dark control; optical radiation <525 nm ≈ 0). Melatonin suppressions after 1-h and 2-h exposures to tablets viewed with the blue light were significantly greater than zero. Suppression levels after 1-h exposure to the tablets-only were not statistically different than zero; however, this difference reached significance after 2 h. Based on these results, display manufacturers can determine how their products will affect melatonin levels and use model predictions to tune the spectral power distribution of self-luminous devices to increase or to decrease stimulation to the circadian system.
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Affiliation(s)
- Brittany Wood
- Lighting Research Center, Rensselaer Polytechnic Institute, 21 Union Street, Troy, NY 12180, USA.
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27
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Perganta G, Barnard AR, Katti C, Vachtsevanos A, Douglas RH, MacLaren RE, Votruba M, Sekaran S. Non-image-forming light driven functions are preserved in a mouse model of autosomal dominant optic atrophy. PLoS One 2013; 8:e56350. [PMID: 23409176 PMCID: PMC3569441 DOI: 10.1371/journal.pone.0056350] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 01/08/2013] [Indexed: 12/19/2022] Open
Abstract
Autosomal dominant optic atrophy (ADOA) is a slowly progressive optic neuropathy that has been associated with mutations of the OPA1 gene. In patients, the disease primarily affects the retinal ganglion cells (RGCs) and causes optic nerve atrophy and visual loss. A subset of RGCs are intrinsically photosensitive, express the photopigment melanopsin and drive non-image-forming (NIF) visual functions including light driven circadian and sleep behaviours and the pupil light reflex. Given the RGC pathology in ADOA, disruption of NIF functions might be predicted. Interestingly in ADOA patients the pupil light reflex was preserved, although NIF behavioural outputs were not examined. The B6; C3-Opa1(Q285STOP) mouse model of ADOA displays optic nerve abnormalities, RGC dendropathy and functional visual disruption. We performed a comprehensive assessment of light driven NIF functions in this mouse model using wheel running activity monitoring, videotracking and pupillometry. Opa1 mutant mice entrained their activity rhythm to the external light/dark cycle, suppressed their activity in response to acute light exposure at night, generated circadian phase shift responses to 480 nm and 525 nm pulses, demonstrated immobility-defined sleep induction following exposure to a brief light pulse at night and exhibited an intensity dependent pupil light reflex. There were no significant differences in any parameter tested relative to wildtype littermate controls. Furthermore, there was no significant difference in the number of melanopsin-expressing RGCs, cell morphology or melanopsin transcript levels between genotypes. Taken together, these findings suggest the preservation of NIF functions in Opa1 mutants. The results provide support to growing evidence that the melanopsin-expressing RGCs are protected in mitochondrial optic neuropathies.
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Affiliation(s)
- Georgia Perganta
- Nuffield Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
| | - Alun R. Barnard
- Nuffield Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
| | - Christiana Katti
- Nuffield Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
| | - Athanasios Vachtsevanos
- Nuffield Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
| | - Ron H. Douglas
- Optometry and Visual Science, City University London, London, United Kingdom
| | - Robert E. MacLaren
- Nuffield Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust and NIHR Biomedical Research Centre, London, United Kingdom
| | - Marcela Votruba
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Sumathi Sekaran
- Nuffield Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom
- * E-mail:
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28
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Mohler E, Frei P, Fröhlich J, Braun-Fahrländer C, Röösli M. Exposure to radiofrequency electromagnetic fields and sleep quality: a prospective cohort study. PLoS One 2012; 7:e37455. [PMID: 22624036 PMCID: PMC3356284 DOI: 10.1371/journal.pone.0037455] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 04/23/2012] [Indexed: 11/19/2022] Open
Abstract
Background There is persistent public concern about sleep disturbances due to radiofrequency electromagnetic field (RF-EMF) exposure. The aim of this prospective cohort study was to investigate whether sleep quality is affected by mobile phone use or by other RF-EMF sources in the everyday environment. Methods We conducted a prospective cohort study with 955 study participants aged between 30 and 60 years. Sleep quality and daytime sleepiness was assessed by means of standardized questionnaires in May 2008 (baseline) and May 2009 (follow-up). We also asked about mobile and cordless phone use and asked study participants for consent to obtain their mobile phone connection data from the mobile phone operators. Exposure to environmental RF-EMF was computed for each study participant using a previously developed and validated prediction model. In a nested sample of 119 study participants, RF-EMF exposure was measured in the bedroom and data on sleep behavior was collected by means of actigraphy during two weeks. Data were analyzed using multivariable regression models adjusted for relevant confounders. Results In the longitudinal analyses neither operator-recorded nor self-reported mobile phone use was associated with sleep disturbances or daytime sleepiness. Also, exposure to environmental RF-EMF did not affect self-reported sleep quality. The results from the longitudinal analyses were confirmed in the nested sleep study with objectively recorded exposure and measured sleep behavior data. Conclusions We did not find evidence for adverse effects on sleep quality from RF-EMF exposure in our everyday environment.
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Affiliation(s)
- Evelyn Mohler
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Patrizia Frei
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jürg Fröhlich
- Laboratory for Electromagnetic Fields and Microwave Electronics, ETH Zürich, Zürich, Switzerland
| | | | - Martin Röösli
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
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29
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Dijk DJ, Duffy JF, Silva EJ, Shanahan TL, Boivin DB, Czeisler CA. Amplitude reduction and phase shifts of melatonin, cortisol and other circadian rhythms after a gradual advance of sleep and light exposure in humans. PLoS One 2012; 7:e30037. [PMID: 22363414 PMCID: PMC3281823 DOI: 10.1371/journal.pone.0030037] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 12/08/2011] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The phase and amplitude of rhythms in physiology and behavior are generated by circadian oscillators and entrained to the 24-h day by exposure to the light-dark cycle and feedback from the sleep-wake cycle. The extent to which the phase and amplitude of multiple rhythms are similarly affected during altered timing of light exposure and the sleep-wake cycle has not been fully characterized. METHODOLOGY/PRINCIPAL FINDINGS We assessed the phase and amplitude of the rhythms of melatonin, core body temperature, cortisol, alertness, performance and sleep after a perturbation of entrainment by a gradual advance of the sleep-wake schedule (10 h in 5 days) and associated light-dark cycle in 14 healthy men. The light-dark cycle consisted either of moderate intensity 'room' light (∼90-150 lux) or moderate light supplemented with bright light (∼10,000 lux) for 5 to 8 hours following sleep. After the advance of the sleep-wake schedule in moderate light, no significant advance of the melatonin rhythm was observed whereas, after bright light supplementation the phase advance was 8.1 h (SEM 0.7 h). Individual differences in phase shifts correlated across variables. The amplitude of the melatonin rhythm assessed under constant conditions was reduced after moderate light by 54% (17-94%) and after bright light by 52% (range 12-84%), as compared to the amplitude at baseline in the presence of a sleep-wake cycle. Individual differences in amplitude reduction of the melatonin rhythm correlated with the amplitude of body temperature, cortisol and alertness. CONCLUSIONS/SIGNIFICANCE Alterations in the timing of the sleep-wake cycle and associated bright or moderate light exposure can lead to changes in phase and reduction of circadian amplitude which are consistent across multiple variables but differ between individuals. These data have implications for our understanding of circadian organization and the negative health outcomes associated with shift-work, jet-lag and exposure to artificial light.
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Affiliation(s)
- Derk-Jan Dijk
- Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts, United States of America.
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30
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Arias P, Vivas J, Grieve KL, Cudeiro J. Double-blind, randomized, placebo controlled trial on the effect of 10 days low-frequency rTMS over the vertex on sleep in Parkinson’s disease. Sleep Med 2010; 11:759-65. [PMID: 20674489 DOI: 10.1016/j.sleep.2010.05.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 05/18/2010] [Accepted: 05/19/2010] [Indexed: 11/18/2022]
Affiliation(s)
- Pablo Arias
- Neuroscience and Motor Control Group (NEUROcom), Department of Medicine-INEF and Institute for Biomedical Research (INIBIC), University of A Coruña, Spain
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31
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Tsai JW, Hannibal J, Hagiwara G, Colas D, Ruppert E, Ruby NF, Heller HC, Franken P, Bourgin P. Melanopsin as a sleep modulator: circadian gating of the direct effects of light on sleep and altered sleep homeostasis in Opn4(-/-) mice. PLoS Biol 2009; 7:e1000125. [PMID: 19513122 PMCID: PMC2688840 DOI: 10.1371/journal.pbio.1000125] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Accepted: 04/28/2009] [Indexed: 11/18/2022] Open
Abstract
Analyses in mice deficient for the blue-light-sensitive photopigment melanopsin show that direct effects of light on behavior and EEG depend on the time of day. The data further suggest an unexpected role for melanopsin in sleep homeostasis. Light influences sleep and alertness either indirectly through a well-characterized circadian pathway or directly through yet poorly understood mechanisms. Melanopsin (Opn4) is a retinal photopigment crucial for conveying nonvisual light information to the brain. Through extensive characterization of sleep and the electrocorticogram (ECoG) in melanopsin-deficient (Opn4−/−) mice under various light–dark (LD) schedules, we assessed the role of melanopsin in mediating the effects of light on sleep and ECoG activity. In control mice, a light pulse given during the habitual dark period readily induced sleep, whereas a dark pulse given during the habitual light period induced waking with pronounced theta (7–10 Hz) and gamma (40–70 Hz) activity, the ECoG correlates of alertness. In contrast, light failed to induce sleep in Opn4−/− mice, and the dark-pulse-induced increase in theta and gamma activity was delayed. A 24-h recording under a LD 1-h∶1-h schedule revealed that the failure to respond to light in Opn4−/− mice was restricted to the subjective dark period. Light induced c-Fos immunoreactivity in the suprachiasmatic nuclei (SCN) and in sleep-active ventrolateral preoptic (VLPO) neurons was importantly reduced in Opn4−/− mice, implicating both sleep-regulatory structures in the melanopsin-mediated effects of light. In addition to these acute light effects, Opn4−/− mice slept 1 h less during the 12-h light period of a LD 12∶12 schedule owing to a lengthening of waking bouts. Despite this reduction in sleep time, ECoG delta power, a marker of sleep need, was decreased in Opn4−/− mice for most of the (subjective) dark period. Delta power reached after a 6-h sleep deprivation was similarly reduced in Opn4−/− mice. In mice, melanopsin's contribution to the direct effects of light on sleep is limited to the dark or active period, suggesting that at this circadian phase, melanopsin compensates for circadian variations in the photo sensitivity of other light-encoding pathways such as rod and cones. Our study, furthermore, demonstrates that lack of melanopsin alters sleep homeostasis. These findings call for a reevaluation of the role of light on mammalian physiology and behavior. Light affects sleep in two ways: indirectly through the phase adjustment of circadian rhythms and directly through nonvisual mechanisms that are independent of the circadian system. The direct effects of light include the promotion of sleep in night-active animals and of alertness in diurnal species. We analyzed sleep and the electroencephalogram (EEG) under various light–dark regimens in mice lacking melanopsin (Opn4−/−), a retinal photopigment crucial for conveying light-level information to the brain, to determine the role of melanopsin, as opposed to rod and cones, in mediating these direct effects of light. We show that melanopsin mediates the direct effects of light during the subjective dark period, whereas rods and cones contribute to these effects in the light period. Our finding that “sleep-active” (i.e., galanin-positive) neurons of the anterior hypothalamus are not activated by light in Opn4−/− mice suggests that these neurons are part of the circuitry whereby light promotes sleep. Also, the alerting effects of transitions into darkness were less pronounced in Opn4−/− mice judged on the reduced increase in EEG theta and gamma activity. Finally, and unexpectedly, the rate at which the need for sleep, quantified as EEG delta power, accumulated during wakefulness was found to be reduced in Opn4−/− mice both during baseline and sleep deprivation conditions, implicating a photopigment in the homeostatic regulation of sleep. We conclude that melanopsin contributes to the direct effects of light and darkness, and in interaction with circadian and homeostatic drive, determines the occurrence and quality of both sleep and waking. If confirmed in humans, our observations will have applications for the clinical use of light as well as for societal lighting conditions.
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Affiliation(s)
- Jessica W. Tsai
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Jens Hannibal
- Department of Clinical Biochemistry, Rigshopitalet, Copenhagen, Denmark
| | - Grace Hagiwara
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Damien Colas
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Elisabeth Ruppert
- Laboratory of Rhythms - CNRS UMR 7168/LC2, Louis Pasteur University and Department of Neurology - School of Medicine, Strasbourg, France
| | - Norman F. Ruby
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - H. Craig Heller
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Paul Franken
- Department of Biology, Stanford University, Stanford, California, United States of America
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne-Dorigny, Switzerland
- * E-mail: (PF); (PB)
| | - Patrice Bourgin
- Department of Biology, Stanford University, Stanford, California, United States of America
- Laboratory of Rhythms - CNRS UMR 7168/LC2, Louis Pasteur University and Department of Neurology - School of Medicine, Strasbourg, France
- * E-mail: (PF); (PB)
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Sinha RK, Aggarwal Y, Upadhyay PK, Dwivedi A, Keshri AK, Das BN. Neural network-based evaluation of chronic non-thermal effects of modulated 2450 MHz microwave radiation on electroencephalogram. Ann Biomed Eng 2008; 36:839-51. [PMID: 18259868 DOI: 10.1007/s10439-008-9450-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Accepted: 01/28/2008] [Indexed: 11/26/2022]
Abstract
The effects of chronic exposure (2 h daily for 21 days) of 1 kHz square wave-modulated 2450 MHz microwave radiation (non-thermal) on sleep-EEG, open field behavior, and thyroid hormones (T(3), T(4), and TSH) have been analyzed in an animal model. Results revealed significant changes in these pathophysiological parameters (p < 0.05 or better), except body temperature, grooming behavior, and TSH levels. The sleep-EEG power spectrum data for slow wave sleep (SWS), rapid eye movement (REM) sleep, and awake (AWA) states in two experimental groups of rats (microwave exposed and the control) were tested by an artificial neural network (ANN), containing 60 nodes in input layer, weighted from power spectrum data from 0 to 30 Hz, 18 nodes in hidden layer and an output node. The target output values for this network were determined with another five-layered neural network (with the structure of 6-14-1-14-6). The input and output of this network was assigned with the six confirmed pathophysiological changes. The most important feature for chronic exposure of 2450 MHz microwave exposure and for control subjects was extracted from the third layer single neuron and used as the target value for the three-layered ANN. The network was found effective in recognizing the EEG power spectra with an average of 71.93% for microwave exposure and 93.13% for control subjects, respectively. However, the lower percentage of pattern identification agreement in the microwave-exposed group in comparison to the control group suggest only mild effects of microwave exposure with this experimental setup.
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Affiliation(s)
- Rakesh Kumar Sinha
- Department of Biomedical Instrumentation, Birla Institute of Technology, Mesra, Ranchi, Jharkhand 835215, India.
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Mongrain V, Paquet J, Dumont M. Contribution of the photoperiod at birth to the association between season of birth and diurnal preference. Neurosci Lett 2006; 406:113-6. [PMID: 16889896 DOI: 10.1016/j.neulet.2006.07.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 07/05/2006] [Accepted: 07/11/2006] [Indexed: 11/25/2022]
Abstract
The aim of the present study was to evaluate the influence of season of birth and photoperiod at birth on diurnal preference in young adults. Participants were 1591 volunteers aged 17-35 years (69% women). The scores obtained on the Morningness-Eveningness Questionnaire (MEQ) of Horne and Ostberg were first assessed as a function of gender and season of birth by a two-way ANOVA. Results revealed a higher MEQ score (reflecting more morningness) in women than in men, and in individuals born during autumn than in those born during spring. There was no gender-by-season interaction. The MEQ scores of four categories of photoperiod at birth were also compared. Individuals born during short photoperiods of 8-10h showed stronger morningness than individuals born during photoperiods of 12-14 h. The highest morningness scores were observed in subjects born during 8-10h photoperiods in the autumn. By contrast, diurnal preference of subjects born during 8-10h photoperiods in the winter did not differ from diurnal preference of subjects born during longer photoperiods. Our results add support to previous reports showing an association between season of birth and morningness-eveningness, but this association cannot be explained entirely by the length of the photoperiod at birth. We suggest that the association between season of birth and diurnal preference reflects an influence of light intensity and/or variations in photoperiod during early development on the characteristics of the circadian system.
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Affiliation(s)
- Valérie Mongrain
- Chronobiology Laboratory, Sacré-Coeur Hospital of Montréal, Que., Canada
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Abdel-Rassoul G, El-Fateh OA, Salem MA, Michael A, Farahat F, El-Batanouny M, Salem E. Neurobehavioral effects among inhabitants around mobile phone base stations. Neurotoxicology 2006; 28:434-40. [PMID: 16962663 DOI: 10.1016/j.neuro.2006.07.012] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Revised: 06/17/2006] [Accepted: 07/18/2006] [Indexed: 11/21/2022]
Abstract
BACKGROUND There is a general concern on the possible hazardous health effects of exposure to radiofrequency electromagnetic radiations (RFR) emitted from mobile phone base station antennas on the human nervous system. AIM To identify the possible neurobehavioral deficits among inhabitants living nearby mobile phone base stations. METHODS A cross-sectional study was conducted on (85) inhabitants living nearby the first mobile phone station antenna in Menoufiya governorate, Egypt, 37 are living in a building under the station antenna while 48 opposite the station. A control group (80) participants were matched with the exposed for age, sex, occupation and educational level. All participants completed a structured questionnaire containing: personal, educational and medical histories; general and neurological examinations; neurobehavioral test battery (NBTB) [involving tests for visuomotor speed, problem solving, attention and memory]; in addition to Eysenck personality questionnaire (EPQ). RESULTS The prevalence of neuropsychiatric complaints as headache (23.5%), memory changes (28.2%), dizziness (18.8%), tremors (9.4%), depressive symptoms (21.7%), and sleep disturbance (23.5%) were significantly higher among exposed inhabitants than controls: (10%), (5%), (5%), (0%), (8.8%) and (10%), respectively (P<0.05). The NBTB indicated that the exposed inhabitants exhibited a significantly lower performance than controls in one of the tests of attention and short-term auditory memory [Paced Auditory Serial Addition Test (PASAT)]. Also, the inhabitants opposite the station exhibited a lower performance in the problem solving test (block design) than those under the station. All inhabitants exhibited a better performance in the two tests of visuomotor speed (Digit symbol and Trailmaking B) and one test of attention (Trailmaking A) than controls. The last available measures of RFR emitted from the first mobile phone base station antennas in Menoufiya governorate were less than the allowable standard level. CONCLUSIONS AND RECOMMENDATIONS Inhabitants living nearby mobile phone base stations are at risk for developing neuropsychiatric problems and some changes in the performance of neurobehavioral functions either by facilitation or inhibition. So, revision of standard guidelines for public exposure to RER from mobile phone base station antennas and using of NBTB for regular assessment and early detection of biological effects among inhabitants around the stations are recommended.
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Affiliation(s)
- G Abdel-Rassoul
- Community, Environmental and Occupational Medicine Department, Faculty of Medicine, Menoufiya University, Shebin El-Kom, Egypt.
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Pitman JL, McGill JJ, Keegan KP, Allada R. A dynamic role for the mushroom bodies in promoting sleep in Drosophila. Nature 2006; 441:753-6. [PMID: 16760979 DOI: 10.1038/nature04739] [Citation(s) in RCA: 235] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Accepted: 03/21/2006] [Indexed: 11/08/2022]
Abstract
The fruitfly, Drosophila melanogaster, exhibits many of the cardinal features of sleep, yet little is known about the neural circuits governing its sleep. Here we have performed a screen of GAL4 lines expressing a temperature-sensitive synaptic blocker shibire(ts1) (ref. 2) in a range of discrete neural circuits, and assayed the amount of sleep at different temperatures. We identified three short-sleep lines at the restrictive temperature with shared expression in the mushroom bodies, a neural locus central to learning and memory. Chemical ablation of the mushroom bodies also resulted in reduced sleep. These studies highlight a central role for the mushroom bodies in sleep regulation.
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Affiliation(s)
- Jena L Pitman
- Department of Neurobiology and Physiology, Northwestern University, Evanston, Ilinois 60208, USA
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Takasu NN, Hashimoto S, Yamanaka Y, Tanahashi Y, Yamazaki A, Honma S, Honma KI. Repeated exposures to daytime bright light increase nocturnal melatonin rise and maintain circadian phase in young subjects under fixed sleep schedule. Am J Physiol Regul Integr Comp Physiol 2006; 291:R1799-807. [PMID: 16840653 DOI: 10.1152/ajpregu.00211.2006] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Effects of two different light intensities during daytime were examined on human circadian rhythms in plasma melatonin, core body temperature, and wrist activity under a fixed sleep schedule. Sleep qualities as indicated by polysomnography and subjective sleepiness were also measured. In the first week, under dim light conditions ( approximately 10 lx), the onset and peak of nocturnal melatonin rise were significantly delayed, whereas the end of melatonin rise was not changed. The peak level of melatonin rise was not affected. As a result, the width of nocturnal melatonin rise was significantly shortened. In the second week, under bright light conditions ( approximately 5,000 lx), the phases of nocturnal melatonin rise were not changed further, but the peak level was significantly increased. Core body temperature at the initial sleep phase was progressively elevated during the course of dim light exposure and reached the maximum level at the first night of bright light conditions. Subjective sleepiness gradually declined in the course of dim light exposure and reached the minimum level at the first day of bright light. These findings indicate that repeated exposures to daytime bright light are effective in controlling the circadian phase and increasing the peak level of nocturnal melatonin rise in plasma and suggest a close correlation between phase-delay shifts of the onset of nocturnal melatonin rise or body temperature rhythm and daytime sleepiness.
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Affiliation(s)
- Nana N Takasu
- Department of Physiology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
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Aristakesian EA, Kuzik VV, Makina DM, Oganesian GA. [Sleep-waking cycle and hypothalamo-hypophysis neurosecretory system of young rats at photostimulation]. Zh Evol Biokhim Fiziol 2006; 42:244-52. [PMID: 16808283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
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Münch M, Kobialka S, Steiner R, Oelhafen P, Wirz-Justice A, Cajochen C. Wavelength-dependent effects of evening light exposure on sleep architecture and sleep EEG power density in men. Am J Physiol Regul Integr Comp Physiol 2006; 290:R1421-8. [PMID: 16439671 DOI: 10.1152/ajpregu.00478.2005] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Light strongly influences the circadian timing system in humans via non-image-forming photoreceptors in the retinal ganglion cells. Their spectral sensitivity is highest in the short-wavelength range of the visible light spectrum as demonstrated by melatonin suppression, circadian phase shifting, acute physiological responses, and subjective alertness. We tested the impact of short wavelength light (460 nm) on sleep EEG power spectra and sleep architecture. We hypothesized that its acute action on sleep is similar in magnitude to reported effects for polychromatic light at higher intensities and stronger than longer wavelength light (550 nm). The sleep EEGs of eight young men were analyzed after 2-h evening exposure to blue (460 nm) and green (550 nm) light of equal photon densities (2.8 × 1013 photons·cm−2·s−1) and to dark (0 lux) under constant posture conditions. The time course of EEG slow-wave activity (SWA; 0.75–4.5 Hz) across sleep cycles after blue light at 460 nm was changed such that SWA was slightly reduced in the first and significantly increased during the third sleep cycle in parietal and occipital brain regions. Moreover, blue light significantly shortened rapid eye movement (REM) sleep duration during these two sleep cycles. Thus the light effects on the dynamics of SWA and REM sleep durations were blue shifted relative to the three-cone visual photopic system probably mediated by the circadian, non-image-forming visual system. Our results can be interpreted in terms of an induction of a circadian phase delay and/or repercussions of a stronger alerting effect after blue light, persisting into the sleep episode.
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Affiliation(s)
- Mirjam Münch
- Centre for Chronobiology, Psychiatric Univ. Clinics, University of Basel, Switzerland
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Abstract
With age, the consolidation of nocturnal sleep decreases, daytime napping increases, and sleep occurs earlier. Sleep regulation is dependent on the interaction between a circadian pacemaker (biological clock) and the sleep homeostat (sleep pressure increasing with duration of time awake). We have shown that in the healthy elderly, the amplitude of circadian rhythms (e. g. melatonin secretion) declines, as does slow wave sleep, parallel with an increase in afternoon sleepiness and a tendency to fall asleep in the early evening when younger subjects do not. Light is the major zeitgeber to stabilise the biological clock: older subjects require sufficient light exposure during daytime and in the evening, and should take no or only brief naps during the day to improve sleep.
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Affiliation(s)
- M Münch
- Zentrum der Chronobiologie, Universitäre Psychiatrische Kliniken, Wilhelm-Klein-Strasse 27, 4025, Basel, Schweiz
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Abstract
Previous research has suggested that exposure to radiofrequency electromagnetic fields increases electroencephalogram spectral power in non-rapid eye movement sleep. Other sleep parameters have also been affected following exposure. We examined whether aspects of sleep architecture show sensitivity to electromagnetic fields emitted by digital mobile phone handsets. Fifty participants were exposed to electromagnetic fields for 30 min prior to sleep. Results showed a decrease in rapid eye movement sleep latency and increased electroencephalogram spectral power in the 11.5-12.25 Hz frequency range during the initial part of sleep following exposure. These results are evidence that mobile phone exposure prior to sleep may promote rapid eye movement sleep and modify the sleep electroencephalogram in the first non-rapid eye movement sleep period.
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Affiliation(s)
- Sarah P Loughran
- Brain Sciences Institute, Swinburne University of Technology, Hawthorn, Victoria, Australia
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Revell VL, Burgess HJ, Gazda CJ, Smith MR, Fogg LF, Eastman CI. Advancing human circadian rhythms with afternoon melatonin and morning intermittent bright light. J Clin Endocrinol Metab 2006; 91:54-9. [PMID: 16263827 PMCID: PMC3841985 DOI: 10.1210/jc.2005-1009] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Both light and melatonin can be used to phase shift the human circadian clock, but the phase-advancing effect of the combination has not been extensively investigated. OBJECTIVE The objective of the study was to determine whether phase advances induced by morning intermittent bright light and a gradually advancing sleep schedule could be increased with afternoon melatonin. PARTICIPANTS Healthy adults (25 males, 19 females, between the ages of 19 and 45 yr) participated in the study. DESIGN There were 3 d of a gradually advancing sleep/dark period (wake time 1 h earlier each morning), bright light on awakening [four 30-min bright-light pulses (approximately 5000 lux) alternating with 30 min room light < 60 lux] and afternoon melatonin, either 0.5 or 3.0 mg melatonin timed to induce maximal phase advances, or matching placebo. The dim light melatonin onset was measured before and after the treatment to determine the phase advance. RESULTS There were significantly larger phase advances with 0.5 mg (2.5 h, n = 16) and 3.0 mg melatonin (2.6 h, n = 13), compared with placebo (1.7 h, n = 15), but there was no difference between the two melatonin doses. Subjects did not experience jet lag-type symptoms during the 3-d treatment CONCLUSIONS Afternoon melatonin, morning intermittent bright light, and a gradually advancing sleep schedule advanced circadian rhythms almost 1 h/d and thus produced very little circadian misalignment. This treatment could be used in any situation in which people need to phase advance their circadian clock, such as before eastward jet travel or for delayed sleep phase syndrome.
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Affiliation(s)
- Victoria L Revell
- Biological Rhythms Research Lab, Rush University Medical Center, Chicago, Illinois 60612, USA
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Altpeter ES, Röösli M, Battaglia M, Pfluger D, Minder CE, Abelin T. Effect of short-wave (6-22 MHz) magnetic fields on sleep quality and melatonin cycle in humans: the Schwarzenburg shut-down study. Bioelectromagnetics 2006; 27:142-50. [PMID: 16342198 DOI: 10.1002/bem.20183] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This paper describes the results of a unique "natural experiment" of the operation and cessation of a broadcast transmitter with its short-wave electromagnetic fields (6-22 MHz) on sleep quality and melatonin cycle in a general human population sample. In 1998, 54 volunteers (21 men, 33 women) were followed for 1 week each before and after shut-down of the short-wave radio transmitter at Schwarzenburg (Switzerland). Salivary melatonin was sampled five times a day and total daily excretion and acrophase were estimated using complex cosinor analysis. Sleep quality was recorded daily using a visual analogue scale. Before shut down, self-rated sleep quality was reduced by 3.9 units (95% CI: 1.7-6.0) per mA/m increase in magnetic field exposure. The corresponding decrease in melatonin excretion was 10% (95% CI: -32 to 20%). After shutdown, sleep quality improved by 1.7 units (95% CI: 0.1-3.4) per mA/m decrease in magnetic field exposure. Melatonin excretion increased by 15% (95% CI: -3 to 36%) compared to baseline values suggesting a rebound effect. Stratified analyses showed an exposure effect on melatonin excretion in poor sleepers (26% increase; 95% CI: 8-47%) but not in good sleepers. Change in sleep quality and melatonin excretion was related to the extent of magnetic field reduction after the transmitter's shut down in poor but not good sleepers. However, blinding of exposure was not possible in this observational study and this may have affected the outcome measurements in a direct or indirect (psychological) way.
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Rattenborg NC, Obermeyer WH, Vacha E, Benca RM. Acute effects of light and darkness on sleep in the pigeon (Columba livia). Physiol Behav 2005; 84:635-40. [PMID: 15811399 DOI: 10.1016/j.physbeh.2005.02.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2004] [Revised: 01/12/2005] [Accepted: 02/10/2005] [Indexed: 10/25/2022]
Abstract
In addition to entraining circadian rhythms, light has acute effects on sleep and wakefulness in mammals. To determine whether light and darkness have similar effects in birds, the only non-mammalian group that displays sleep patterns comparable to mammals, we examined the effects of lighting changes on sleep and wakefulness in the pigeon. We quantified sleep behavior (i.e., bilateral or unilateral eye closure) in pigeons maintained under a 12:12 LD cycle, and immediately following a change from a 12:12 to a 3:3 LD cycle. During both LD cycles, sleep was most prevalent during dark periods. During the 3:3 LD cycle, darkness had the greatest sleep promoting effect during the hours corresponding to the subjective night of the preceding 12:12 LD cycle, whereas light suppressed sleep across circadian phases. As previously suggested, the light-induced decrease in sleep in the subjective night might be partly mediated by the suppression of melatonin by light. Although the sleep promoting effect of darkness was modulated by the circadian rhythm, sleep in darkness occurred during all circadian phases, suggesting that darkness per se may play a direct role in inducing sleep. In addition to the effects of lighting on behavioral state, we observed an overall bias toward more right eye closure under all lighting conditions, possibly reflecting a response to the novel testing environment.
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Affiliation(s)
- Niels C Rattenborg
- Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Blvd. Madison, WI 53719, USA
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Kozaki T, Kitamura S, Higashihara Y, Ishibashi K, Noguchi H, Yasukouchi A. Effect of color temperature of light sources on slow-wave sleep. ACTA ACUST UNITED AC 2005; 24:183-6. [PMID: 15840951 DOI: 10.2114/jpa.24.183] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In order to examine whether the spectral compositions of light source may affect sleep quality, sleep architecture under different color temperatures of light sources was evaluated. Seven healthy males were exposed to the light sources of different color temperatures (3000 K, 5000 K and 6700 K) for 6.5 h before sleep. The horizontal illuminance level was kept at 1000 lux. Subjects slept on a bed in near darkness (< 10 lux) after extinguishing the light, and polysomnograms recorded the sleep parameters. In the early phase of the sleep period, the amount of stage-4 sleep (S4-sleep) was significantly attenuated under the higher color temperature of 6700 K compared with the lower color temperature of 3000 K. Present findings suggest that light sources with higher color temperatures may affect sleep quality in a view that S4-sleep period is important for sleep quality.
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Affiliation(s)
- Tomoaki Kozaki
- Department of Physiological Anthropology, Faculty of Design, Kyushu University, Japan.
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45
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Grigor'ev IG. [The electromagnetic fields of cellular phones and the health of children and of teenagers (the situation requiring to take an urgent measure)]. Radiats Biol Radioecol 2005; 45:442-50. [PMID: 16209190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The problem of the influence of electromagnetic fields (EMF) of cellular phones (CP) on the health of children and teenagers is considered in this article. The results of the researchs indicate the increased sensitivity of the children and of the teenagers to this kind of radiation. Direct indicators of electromagnetic influence can be infringement of sleep, decrease of the memory, fatigue, breach of a blood-brain barrier permeability, changes in nervous cells of a brain. As the remote consequences the development of tumors of a brain and acoustic nerve are predicted. However all these results require the realization of independent repeated researches. WHO (World Health Organization) recommends to use "Precautionary principle" with the purposes of decreasing of the risk. Russian National Committee of Non-Ionizing Radiation Protection recommended to limit the use of CP by children and teenagers under 16 years old (2002, February 2004). The corresponding recommendations were included into SunPin H2.1.8/2.2.4.1190-03/(2003).
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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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47
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Fucci RL, Gardner J, Hanifin JP, Jasser S, Byrne B, Gerner E, Rollag M, Brainard GC. Toward optimizing lighting as a countermeasure to sleep and circadian disruption in space flight. Acta Astronaut 2005; 56:1017-1024. [PMID: 15838948 DOI: 10.1016/j.actaastro.2005.01.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Light is being used as a pre-launch countermeasure to circadian and sleep disruption in astronauts. The effect of light on the circadian system is readily monitored by measurement of plasma melatonin. Our group has established an action spectrum for human melatonin regulation and determined the region of 446-477 nm to be the most potent for suppressing plasma melatonin. The aim of this study was to compare the efficacy of 460 and 555 nm for suppressing melatonin using a within-subjects design. Subjects (N=12) were exposed to equal photon densities (7.18 x 10(12) photons/cm2/s) at 460 and 555 nm. Melatonin suppression was significantly stronger at 460 nm (p<0.02). An extension to the action spectrum showed that 420 nm light at 16 and 32 microW/cm2 significantly suppressed melatonin (p<0.04 and p<0.002). These studies will help optimize lighting countermeasures to circadian and sleep disruption during spaceflight.
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Affiliation(s)
- Robert L Fucci
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
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48
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Petrova EV, Gulyaeva NV, Titarov SI, Rozhnov YV, Koval'zon VM. Actions of pulsed ultra-broadband electromagnetic irradiation on the EEG and sleep in laboratory animals. Neurosci Behav Physiol 2005; 35:165-70. [PMID: 15779329 DOI: 10.1007/s11055-005-0062-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Irradiation of animals with ultrashort impulses of ultra-broadband magnetic irradiation with an impulse repetition frequency of 6 Hz for 1 h induced changes in the spectral composition of cerebral cortex electrical activity in rats, measured over the 5 min immediately after irradiation, as compared with controls. In particular, there was suppression of frequencies close to the impulse sequence frequency, along with a decrease in interhemisphere coherence. Continuous recording of polygrams for 22 h from rabbits after irradiation revealed a "delayed" effect--a significant increase in paradoxical sleep, starting 16 h after the end of irradiation and persisting to the end of the recording period. It is suggested that irradiation has a direct action both on the mechanisms of generation of the theta rhythm (septohippocampal) and on the system controlling circadian rhythms (the suprachiasmatic nucleus-epiphysis system).
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Affiliation(s)
- E V Petrova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 117865 Moscow, Russia
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49
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Abstract
Light regulates sleep timing through circadian entrapment and by eliciting acute changes in behavior. These behaviors are mediated by the subcortical visual system, retinorecipient nuclei distinct from the geniculocortical system. To test the hypothesis that early visual experience shapes light regulation of behavior, the authors recorded sleep in albino rats reared in continuous dark, continuous light, or a 12-hr light-dark cycle. Dark rearing strengthened and light rearing weakened acute responses to light, including light modulation of REM sleep, a marker for pretectal function in albino rats. However, neither dark nor light rearing altered daily amounts of wakefulness, non-REM sleep, or REM sleep. Thus, light and dark rearing might differentially affect the balance between acute and circadian responses to light that, in concert, govern sleep timing.
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Affiliation(s)
- J Roxanne Prichard
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, USA
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50
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Derégnaucourt S, Mitra PP, Fehér O, Pytte C, Tchernichovski O. How sleep affects the developmental learning of bird song. Nature 2005; 433:710-6. [PMID: 15716944 DOI: 10.1038/nature03275] [Citation(s) in RCA: 246] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Accepted: 12/15/2004] [Indexed: 11/09/2022]
Abstract
Sleep affects learning and development in humans and other animals, but the role of sleep in developmental learning has never been examined. Here we show the effects of night-sleep on song development in the zebra finch by recording and analysing the entire song ontogeny. During periods of rapid learning we observed a pronounced deterioration in song structure after night-sleep. The song regained structure after intense morning singing. Daily improvement in similarity to the tutored song occurred during the late phase of this morning recovery; little further improvement occurred thereafter. Furthermore, birds that showed stronger post-sleep deterioration during development achieved a better final imitation. The effect diminished with age. Our experiments showed that these oscillations were not a result of sleep inertia or lack of practice, indicating the possible involvement of an active process, perhaps neural song-replay during sleep. We suggest that these oscillations correspond to competing demands of plasticity and consolidation during learning, creating repeated opportunities to reshape previously learned motor skills.
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