|   | 
Details
   web
Records
Author Fonken, L.K.; Nelson, R.J.
Title Illuminating the deleterious effects of light at night Type Journal Article
Year 2011 Publication F1000 Medicine Reports Abbreviated Journal F1000 Med Rep
Volume 3 Issue (up) Pages 18
Keywords Human Health; light at night; artificial light; circadian disruption; Review
Abstract Technological advances, while providing many benefits, often create circumstances that differ from the conditions in which we evolved. With the wide-spread adoption of electrical lighting during the 20(th) century, humans became exposed to bright and unnatural light at night for the first time in their evolutionary history. Electrical lighting has led to the wide-scale practice of 24-hour shift-work and has meant that what were once just “daytime” activities now run throughout the night; in many ways Western society now functions on a 24-hour schedule. Recent research suggests that this gain in freedom to function throughout the night may also come with significant repercussions. Disruption of our naturally evolved light and dark cycles can result in a wide range of physiological and behavioral changes with potentially serious medical implications. In this article we will discuss several mechanisms through which light at night may exert its effects on cancer, mood, and obesity, as well as potential ways to ameliorate the impact of light at night.
Address Department of Neuroscience and The Institute for Behavioral Medicine Research The Ohio State University, Columbus, OH 43210 USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1757-5931 ISBN Medium
Area Expedition Conference
Notes PMID:21941596; PMCID:PMC3169904 Approved no
Call Number IDA @ john @ Serial 241
Permanent link to this record
 

 
Author Bedrosian, T.A. (ed)
Title Circadian Disruption by Light at Night: Implications for Mood Type Book Whole
Year 2013 Publication Abbreviated Journal
Volume Issue (up) Pages
Keywords circadian disruption; sleep; light at night; melanopsin; mood; mental health; Mood Disorders; epigenetics; red light
Abstract Life on Earth has adapted to a consistent 24-h solar cycle. Circadian rhythms in physiology and behavior remain synchronized to the environment using light as the most potent entraining cue. During the past century, however, the widespread adoption of electric light has led to `round-the-clock’ societies. Instead of aligning with the environment, individuals follow artificial and often erratic light cycles created by social and work schedules. In particular, exposure to artificial light at night (LAN), termed “light pollution”, has become pervasive over the past 100 years. Virtually every individual living in the U.S. and Europe experiences this aberrant light exposure, and moreover about 20% of the population performs shift work. LAN may disrupt physiological timekeeping, leading to dysregulation of internal processes and misalignment between behavior and the environment. Recent evidence suggests that individuals exposed to excessive LAN, such as night shift workers, have increased risk for depressive disorders, but the biological mechanism remains unspecified. In mammals, intrinsically photosensitive retinal ganglion cells (ipRGCs) project light information to (1) the suprachiasmatic nucleus (SCN) in the hypothalamus, regulating circadian rhythms, and (2) to limbic regions, putatively regulating mood. Thus, LAN has the potential to affect both circadian timekeeping and mood. In this dissertation, I present evidence from rodent studies supporting the novel hypothesis that night-time exposure to light disrupts circadian organization and contributes to depressed mood. First, I consider the physiological and behavioral consequences associated with unnatural exposure to LAN. The effects of LAN on circadian output are considered in terms of locomotor activity, the diurnal cortisol rhythm, and diurnal clock protein expression in the brain in Chapter 2. The influence of LAN on behavior and brain plasticity is discussed, with particular focus on depressive-like behavior (Chapter 3) and effects of SSRI treatment (Chapter 4). Effects of LAN on structural plasticity and gene expression in the brain are described, with emphasis on potential correlates of the depressive-like behavior observed under LAN in Chapter 5. Given the prevalence of LAN exposure and its importance, strategies for reversing the effects are offered. Specifically, eliminating LAN quickly reverses behavioral and physiological effects of exposure as described in Chapter 5. In Chapter 6 I report that administration of a pharmacological cytokine inhibitor prevents depressive-like behaviors in LAN, implicating brain inflammation in the behavioral effect. Finally, I demonstrate in Chapter 7 that exposure to red wavelength LAN reduces the effects on brain and behavior, suggesting that LAN acts through specific retinal pathways involving melanopsin. Taken together, these studies demonstrate the consequences of LAN, but also outline potential avenues for prevention or intervention.
Address Department of Neuroscience and The Institute for Behavioral Medicine Research The Ohio State University
Corporate Author Thesis Ph.D. thesis
Publisher Place of Publication Editor Bedrosian, T.A.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 323
Permanent link to this record
 

 
Author Fuller, G. (ed)
Title The Night Shift: Lighting and Nocturnal Strepsirrhine Care in Zoos Type Book Whole
Year 2013 Publication Abbreviated Journal
Volume Issue (up) Pages
Keywords zoos; light at night; circadian disruption; strepsirrhines; primates; lorises; pottos; lighting design
Abstract Over billions of years of evolution, light from the sun, moon, and stars has provided

organisms with reliable information about the passage of time. Photic cues entrain

the circadian system, allowing animals to perform behaviors critical for survival and

reproduction at optimal times. Modern artificial lighting has drastically altered

environmental light cues. Evidence is accumulating that exposure to light at night

(particularly blue wavelengths) from computer screens, urban light pollution, or as

an occupational hazard of night-shift work has major implications for human health.

Nocturnal animals are the shift workers of zoos; they are generally housed on

reversed light cycles so that daytime visitors can observe their active behaviors. As a

result, they are exposed to artificial light throughout their subjective night. The goal

of this investigation was to examine critically the care of nocturnal strepsirrhine

primates in North American zoos, focusing on lorises (Loris and Nycticebus spp.) and pottos (Perodicticus potto). The general hypothesis was that exhibit lighting design affects activity patterns and circadian physiology in nocturnal strepsirrhines. The

first specific aim was to assess the status of these populations. A multi-institutional husbandry survey revealed little consensus among zoos in lighting design, with both red and blue light commonly used for nocturnal illumination. A review of medical records also revealed high rates of neonate mortality. The second aim was to

develop methods for measuring the effects of exhibit lighting on behavior and

health. The use of actigraphy for automated activity monitoring was explored.

Methods were also developed for measuring salivary melatonin and cortisol as

indicators of circadian disruption. Finally, a multi-institutional study was conducted

comparing behavioral and endocrine responses to red and blue dark phase lighting.

These results showed greater activity levels in strepsirrhines housed under red light than blue. Salivary melatonin concentrations in pottos suggested that blue light

suppressed nocturnal melatonin production at higher intensities, but evidence for

circadian disruption was equivocal. These results add to the growing body of

evidence on the detrimental effects of blue light at night and are a step towards

empirical recommendations for nocturnal lighting design in zoos.
Address Department of Biology, Case Western Reserve University
Corporate Author Thesis Ph.D. thesis
Publisher Place of Publication Editor Fuller, G.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 327
Permanent link to this record
 

 
Author Kayaba, M.; Iwayama, K.; Ogata, H.; Seya, Y.; Tokuyama, K.; Satoh, M.
Title Drowsiness and low energy metabolism in the following morning induced by nocturnal blue light exposure Type Journal Article
Year 2013 Publication Sleep Medicine Abbreviated Journal Sleep Medicine
Volume 14 Issue (up) Pages e166-e167
Keywords blue light; light exposure; light at night; circadian disruption; drowsiness; melatonin; metabolism; sleep
Abstract Introduction

Evening light exposure debilitates the circadian rhythm and elicits sleep disturbance. Blue light peak wavelengths, around 460 nm, suppress melatonin secretion via the non-image-forming system. The effects of nocturnal blue light exposure on sleep have been reported to be specific but rather small (Münch, 2008). This study was designed to assess the effect of nocturnal blue light exposure on sleep and energy metabolism until noon the next day.

Materials and methods

Nine healthy male volunteers aged between 21 and 25 participated in this study which had a balanced cross-over design with intrasubject comparisons. After 2 h dark adaptation, the subjects were exposed to blue light or no light for 2 h. The peak wavelength of the blue LED was 465 nm, and the horizontal irradiance of the blue light at the height of eye was at 7.02fÊW/cm2. Sleep was recorded polysomnographically, and energy metabolism was measured with a whole body indirect calorimeter.

Results

There were no significant differences in sleep architecture and energy metabolism during the night. However, dozing (stages 1 and 2) was significantly higher (26.0 < 29.4 vs 6.3 < 8.1 min, P < 0.05), and energy expenditure, O2 consumption, CO2 production and the thermic effect of food (increase in energy expenditure after breakfast) were significantly lower the following morning in the blue light exposure subjects.

Conclusion

Contrary to our expectation, sleep architecture and energy metabolism during sleep were not affected by evening exposure to blue light. It might be due to our milder intervention by which subjects in a sitting position did not gaze at the light source set on the ceiling, while the subjects in previous studies directly received brighter light via custom built goggles (Cajochen, 2005; Münch, 2008) or gazed at a light source under the influence of mydriatic agents to dilate pupils (Brainard, 2001). New findings of the present study were that dozing (stages 1 and 2) was significantly increased, and energy metabolism was significantly lower the following morning in blue light exposed subjects. This suggests that modulation of the circadian rhythm is affected by nocturnal blue light exposure and the effect continues in the following daytime even if the intervention was mild.
Address University of Tsukuba, Graduate School of Comprehensive Human Sciences, Japan
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1389-9457 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 349
Permanent link to this record
 

 
Author Reiter, R.J.; Rosales-Corral, S.; Coto-Montes, A.; Antonio Boga, J.; Tan, D.X.; Davis, J.M.; Konturek, P.C.; Konturek, S.J.; Brzozowski, T.
Title The photoperiod, circadian regulation and chronodisruption: the requisite interplay between the suprachiasmatic nuclei and the pineal and gut melatonin. Type Journal Article
Year 2011 Publication Journal of Physiology and Pharmacology Abbreviated Journal
Volume 62 Issue (up) Pages 269-274
Keywords Human Health; biological clock; chronodisruption; circadian rhythm; gastrointestinal melatonin; peptic ulcer; pineal gland; suprachiasmatic nucleus
Abstract Biological rhythms are essential for optimal health (1, 2). Throughout the course of human evolution, hominids were exposed to regularly alternating periods of light and dark during every 24-hour period. This evolutionary period, which for humans may have lasted for three million or more years, allowed species to take advantage of the light:dark cycle to adjust their physiology and to synchronize it with the prevailing light:dark environment. To take advantage of this information, vertebrates, including hominids, evolved a group of neurons to monitor the photoperiodic environment and to adjust organismal, organ and cellular function accordingly.

This paired group of light-responsive neurons is located in the mediobasal preoptic area at the diencephalic-telencephalic junction just anterior to the hypothalamus. Since these neurons lie immediately above the decussating axons of the optic nerve, i.e., the optic chiasma, they are named the suprachiasmatic nuclei (SCN) (3, 4). The SCN orchestrate all known circadian rhythms in vertebrates and are referred to as the master biological clock or the central rhythm generator.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ christopher.kyba @ Serial 522
Permanent link to this record