Light, Sleep, and Development

PEDIATRICS ◽  
1987 ◽  
Vol 79 (6) ◽  
pp. 1053-1054
Author(s):  
PENNY GLASS ◽  
GORDON B. AVERY
Keyword(s):  
Intensive Care ◽  
Rem Sleep ◽  
Light Exposure ◽  
Bright Light ◽  
Retinal Damage ◽  
Sleep State ◽  
Intensive Care Nursery ◽  
Light Sleep ◽  
Effect Of Light

In Reply.— Sheldon and Bell express concern for the effect of uncycled nursery light on sleep state and biorhythms in infants. Their concerns seem well founded. A variety of evidence suggests that the effect of light exposure in the intensive care nursery goes beyond the potential for retinal damage. For example, we found differences in sleep state for infants exposed to bright v dim ambient nursery light.1 Bright light was associated with significantly greater amounts of active-REM sleep.

scholarly journals Modulation of recognition memory performance by light requires both melanopsin and classical photoreceptors

2016 ◽  
Vol 283 (1845) ◽  
pp. 20162275 ◽  
Author(s):  
Shu K. E. Tam ◽  
Sibah Hasan ◽  
Steven Hughes ◽  
Mark W. Hankins ◽  
Russell G. Foster ◽  
...  
Keyword(s):  
Object Recognition ◽  
Recognition Memory ◽  
Ganglion Cells ◽  
Light Exposure ◽  
Memory Performance ◽  
Recognition Task ◽  
Bright Light ◽  
Brain Network ◽  
Network Activity ◽  
Effect Of Light

Acute light exposure exerts various effects on physiology and behaviour. Although the effects of light on brain network activity in humans are well demonstrated, the effects of light on cognitive performance are inconclusive, with the size, as well as direction, of the effect depending on the nature of the task. Similarly, in nocturnal rodents, bright light can either facilitate or disrupt performance depending on the type of task employed. Crucially, it is unclear whether the effects of light on behavioural performance are mediated via the classical image-forming rods and cones or the melanopsin-expressing photosensitive retinal ganglion cells. Here, we investigate the modulatory effects of light on memory performance in mice using the spontaneous object recognition task. Importantly, we examine which photoreceptors are required to mediate the effects of light on memory performance. By using a cross-over design, we show that object recognition memory is disrupted when the test phase is conducted under a bright light (350 lux), regardless of the light level in the sample phase (10 or 350 lux), demonstrating that exposure to a bright light at the time of test, rather than at the time of encoding, impairs performance. Strikingly, the modulatory effect of light on memory performance is completely abolished in both melanopsin-deficient and rodless–coneless mice. Our findings provide direct evidence that melanopsin-driven and rod/cone-driven photoresponses are integrated in order to mediate the effect of light on memory performance.

Stimulation of Preterm Infants

1988 ◽  
Vol 10 (5) ◽  
pp. 149-153
Author(s):  
Tiffany Field
Keyword(s):  
Intensive Care ◽  
Gestational Age ◽  
Neonatal Intensive Care ◽  
Preterm Neonate ◽  
Sensory Deprivation ◽  
Bright Light ◽  
Preterm Neonates ◽  
Limited Data ◽  
Intensive Care Nursery ◽  
Continuous Noise

Preterm neonates are deprived of their final weeks in utero and may also be deprived of appropriate extrauterine stimulation. The environment of the incubator features bright light and continuous noise, and the neonates are handled infrequently and only briefly. Although the effects of this environment are virtually unknown, some have suggested that the neonatal intensive care nursery may constitute a source of sensory deprivation. Others have suggested that preterm neonates may be overstimulated or, at the very least, may experience inappropriate patterns, rather than inadequate amounts, of stimulation. Despite the limited data regarding the effects of routine stimulation in the intensive care nursery environment, a number of clinicians and researchers have provided stimulation experiences for preterm neonates and have investigated the effects of these. STIMULATION STUDIES The types of interventions provided for preterm neonates have included those that are thought to mimic the environment of the womb or the outside world. Some have viewed the preterm neonate as an extrauterine fetus, whereas others consider that the preterm neonate differs from the fetus insofar as sensory systems undergo physiologic changes at birth. Different forms of stimulation may be necessary for extrauterine development than for intrauterine maturation regardless of gestational age. Stimulation is usually begun as soon as possible after birth and continues until the infant approximates term gestational age, regains birth weight, or is discharged.

Nonphotic entrainment of the human circadian pacemaker

1998 ◽  
Vol 274 (4) ◽  
pp. R991-R996 ◽  
Author(s):  
Elizabeth B. Klerman ◽  
David W. Rimmer ◽  
Derk-Jan Dijk ◽  
Richard E. Kronauer ◽  
Joseph F. Rizzo ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Light Exposure ◽  
Core Body Temperature ◽  
Biological Clock ◽  
Bright Light ◽  
Circadian Pacemaker ◽  
Temperature Rhythms ◽  
Blind Individuals ◽  
Nonphotic Entrainment ◽  
Core Body

In organisms as diverse as single-celled algae and humans, light is the primary stimulus mediating entrainment of the circadian biological clock. Reports that some totally blind individuals appear entrained to the 24-h day have suggested that nonphotic stimuli may also be effective circadian synchronizers in humans, although the nonphotic stimuli are probably comparatively weak synchronizers, because the circadian rhythms of many totally blind individuals “free run” even when they maintain a 24-h activity-rest schedule. To investigate entrainment by nonphotic synchronizers, we studied the endogenous circadian melatonin and core body temperature rhythms of 15 totally blind subjects who lacked conscious light perception and exhibited no suppression of plasma melatonin in response to ocular bright-light exposure. Nine of these fifteen blind individuals were able to maintain synchronization to the 24-h day, albeit often at an atypical phase angle of entrainment. Nonphotic stimuli also synchronized the endogenous circadian rhythms of a totally blind individual to a non-24-h schedule while living in constant near darkness. We conclude that nonphotic stimuli can entrain the human circadian pacemaker in some individuals lacking ocular circadian photoreception.

scholarly journals Critical Effects on Akt Signaling in Adult Zebrafish Brain Following Alterations in Light Exposure

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 637
Author(s):  
Nicholas S. Moore ◽  
Robert A. Mans ◽  
Mackenzee K. McCauley ◽  
Colton S. Allgood ◽  
Keri A. Barksdale
Keyword(s):  
Optic Tectum ◽  
Visual Processing ◽  
Environmental Enrichment ◽  
Glycogen Synthase ◽  
Light Exposure ◽  
Hsp70 Expression ◽  
Light Cycle ◽  
Adult Zebrafish ◽  
Sleep State ◽  
Zebrafish Brain

Evidence from human and animal studies indicate that disrupted light cycles leads to alterations of the sleep state, poor cognition, and the risk of developing neuroinflammatory and generalized health disorders. Zebrafish exhibit a diurnal circadian rhythm and are an increasingly popular model in studies of neurophysiology and neuropathophysiology. Here, we investigate the effect of alterations in light cycle on the adult zebrafish brain: we measured the effect of altered, unpredictable light exposure in adult zebrafish telencephalon, homologous to mammalian hippocampus, and the optic tectum, a significant visual processing center with extensive telencephalon connections. The expression of heat shock protein-70 (HSP70), an important cell stress mediator, was significantly decreased in optic tectum of adult zebrafish brain following four days of altered light exposure. Further, pSer473-Akt (protein kinase B) was significantly reduced in telencephalon following light cycle alteration, and pSer9-GSK3β (glycogen synthase kinase-3β) was significantly reduced in both the telencephalon and optic tectum of light-altered fish. Animals exposed to five minutes of environmental enrichment showed significant increase in pSer473Akt, which was significantly attenuated by four days of altered light exposure. These data show for the first time that unpredictable light exposure alters HSP70 expression and dysregulates Akt-GSK3β signaling in the adult zebrafish brain.

Dry eye following cataract surgery: The effect of light exposure using an in-vitro model

2018 ◽  
Vol 41 (1) ◽  
pp. 128-131 ◽  
Author(s):  
Tugce Ipek ◽  
Mariana Petronela Hanga ◽  
Andreas Hartwig ◽  
James Wolffsohn ◽  
Clare O’Donnell
Keyword(s):  
Cataract Surgery ◽  
Dry Eye ◽  
In Vitro Model ◽  
Light Exposure ◽  
Vitro Model ◽  
Effect Of Light

scholarly journals Fundamentals of circadian entrainment by light

2021 ◽  
Vol 53 (5) ◽  
pp. 377-393
Author(s):  
RG Foster
Keyword(s):  
Ganglion Cells ◽  
Light Exposure ◽  
Bright Light ◽  
Evidence Based ◽  
Retinal Ganglion ◽  
Rods And Cones ◽  
Long Duration ◽  
Lighting Systems ◽  
Short Wavelength Light ◽  
Wavelength Light

Light at dawn and dusk is the key signal for the entrainment of the circadian clock. Light at dusk delays the clock. Light at dawn advances the clock. The threshold for human entrainment requires relatively bright light for a long duration, but the precise irradiance/duration relationships for photoentrainment have yet to be fully defined. Photoentrainment is achieved by a network of photosensitive retinal ganglion cells (pRGCs) which utilise the short-wavelength light-sensitive photopigment, melanopsin. Although rods and cones are not required, they do play a role in photoentrainment, by projecting to and modulating the endogenous photosensitivity of the pRGCs, but in a manner that remains poorly understood. It is also important to emphasise that the age and prior light exposure of an individual will modify the efficacy of entrainment stimuli. Because of the complexity of photoreceptor interactions, attempts to develop evidence-based human centric lighting are not straightforward. We need to study how humans respond to dynamic light exposure in the ‘real world’ where light intensity, duration, spectral quality and the time of exposure vary greatly. Defining these parameters will allow the development of electric lighting systems that will enhance human circadian entrainment.

INTERACTIONS OF THE PINEAL AND EXPOSURE TO CONTINUOUS LIGHT ON ORGAN WEIGHTS OF FEMALE RATS

1961 ◽  
Vol 36 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Richard Jay Wurtman ◽  
Willard Roth ◽  
Mark D. Altschule ◽  
Judith J. Wurtman
Keyword(s):  
Light Exposure ◽  
Continuous Light ◽  
Female Rats ◽  
Constant Light ◽  
Ovarian Weight ◽  
Organ Weights ◽  
Bovine Pineal Extracts ◽  
Pineal Extracts ◽  
Effect Of Light

ABSTRACT Either exposure to constant light for 80 days or pinealectomy produced similar changes in the weights of the ovaries and adrenals of female rats. These were not additive when both procedures were employed. Pinealectomy did not share with light-exposure the capacity to induce uterine hypertrophy. Rats exposed to constant light for 56 days had lighter pineals than animals kept in darkness; this decrease was not affected by administration of bovine pineal extracts. The increase in ovarian weight produced in rats by exposure to light for 56 days was prevented by bovine pineal extracts, but these extracts were without effect on the uterine hypertrophy produced under the same conditions. These data suggest that the effect of light upon the weight of the ovary is mediated via the pineal.

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