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https://www.readbyqxmd.com/read/28801634/mapping-physiological-inputs-from-multiple-photoreceptor-systems-to-dopaminergic-amacrine-cells-in-the-mouse-retina
#1
Xiwu Zhao, Kwoon Y Wong, Dao-Qi Zhang
In the vertebrate retina, dopamine is synthesized and released by a specialized type of amacrine cell, the dopaminergic amacrine cell (DAC). DAC activity is stimulated by rods, cones, and melanopsin-expressing intrinsically photosensitive retinal ganglion cells upon illumination. However, the relative contributions of these three photoreceptor systems to the DAC light-induced response are unknown. Here we found that rods excite dark-adapted DACs across a wide range of stimulation intensities, primarily through connexin-36-dependent rod pathways...
August 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28790405/differential-impact-in-young-and-older-individuals-of-blue-enriched-white-light-on-circadian-physiology-and-alertness-during-sustained-wakefulness
#2
Virginie Gabel, Carolin F Reichert, Micheline Maire, Christina Schmidt, Luc J M Schlangen, Vitaliy Kolodyazhniy, Corrado Garbazza, Christian Cajochen, Antoine U Viola
We tested the effect of different lights as a countermeasure against sleep-loss decrements in alertness, melatonin and cortisol profile, skin temperature and wrist motor activity in healthy young and older volunteers under extendend wakefulness. 26 young [mean (SE): 25.0 (0.6) y)] and 12 older participants [(mean (SE): 63.6 (1.3) y)] underwent 40-h of sustained wakefulness during 3 balanced crossover segments, once under dim light (DL: 8 lx), and once under either white light (WL: 250 lx, 2,800 K) or blue-enriched white light (BL: 250 lx, 9,000 K) exposure...
August 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28774755/human-seasonal-and-circadian-studies-in-antarctica-halley-75-0-s
#3
Josephine Arendt, Benita Middleton
Living for extended periods in Antarctica exposes base personnel to extremes of daylength (photoperiod) and temperature. At the British Antarctic Survey base of Halley, 75(0)S, the sun does not rise for 110 d in the winter and does not set for 100 d in summer. Photoperiod is the major time cue governing the timing of seasonal events such as reproduction in many species. The neuroendocrine signal providing photoperiodic information to body physiology is the duration of melatonin secretion which reflects the length of the night: longer in the short days of winter and shorter in summer...
July 31, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28770653/simple-lighting-manipulations-facilitate-behavioral-entrainment-of-mice-to-18-h-days
#4
Thijs J Walbeek, Michael R Gorman
In an invariantly rhythmic world, a robust and stable mammalian circadian clock is presumed to confer fitness advantages. In shift-work or after rapid transmeridian travel, however, a stable clock might be maladaptive and a more flexibly resettable clock may have advantages. The rate at which rodents can adjust to simulated time zone travel and the range of entrainment can be markedly increased through simple light manipulations, namely, by exposing animals to extremely dim light (<0.01 lux) at night or by bifurcating rhythms under 24-h light-dark-light-dark (LDLD) cycles...
July 1, 2017: Journal of Biological Rhythms
https://www.readbyqxmd.com/read/28760697/vision-in-laboratory-rodents-tools-to-measure-it-and-implications-for-behavioral-research
#5
REVIEW
Henri Leinonen, Heikki Tanila
Mice and rats are nocturnal mammals and their vision is specialized for detection of motion and contrast in dim light conditions. These species possess a large proportion of UV-sensitive cones in their retinas and the majority of their optic nerve axons target superior colliculus rather than visual cortex. Therefore, it was a widely held belief that laboratory rodents hardly utilize vision during day-time behavior. This dogma is being questioned as accumulating evidence suggests that laboratory rodents are able to perform complex visual functions, such as perceiving subjective contours, and that declined vision may affect their performance in many behavioral tasks...
July 28, 2017: Behavioural Brain Research
https://www.readbyqxmd.com/read/28747438/palmitoylation-is-a-prerequisite-for-dimerization-dependent-raftophilicity-of-rhodopsin
#6
Keiji Seno, Fumio Hayashi
The visual photopigment rhodopsin (Rh) is a prototypical G protein-coupled receptor (GPCR) responsible for initiation of the phototransduction cascade in rod photoreceptors. Similar to other GPCRs, Rh can form dimers or even higher oligomers, and tends to have a supramolecular organization that is likely important in the dim light response. Rh also exhibits high affinity for lipid rafts (raftophilicity) upon light-dependent binding with cognate G protein transducin (Gt), suggesting the presence of lipid raft-like domains in the retinal disk membrane and their importance in phototransduction...
July 26, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28739369/genomic-regression-of-claw-keratin-taste-receptor-and-light-associated-genes-provides-insights-into-biology-and-evolutionary-origins-of-snakes
#7
Christopher A Emerling
Regressive evolution of anatomical traits often corresponds with the regression of genomic loci underlying such characters. As such, studying patterns of gene loss can be instrumental in addressing questions of gene function, resolving conflicting results from anatomical studies, and understanding the evolutionary history of clades. The evolutionary origins of snakes involved the regression of a number of anatomical traits, including limbs, taste buds and the visual system, and by analyzing serpent genomes, I was able to test three hypotheses associated with the regression of these features...
July 21, 2017: Molecular Phylogenetics and Evolution
https://www.readbyqxmd.com/read/28731695/how-rhodopsin-tunes-the-equilibrium-between-protonated-and-deprotonated-forms-of-the-retinal-chromophore
#8
Siri C van Keulen, Alicia Solano, Ursula Rothlisberger
Rhodopsin is a photoactive G-protein-coupled receptor (GPCR) that converts dim light into a signal for the brain, leading to eyesight. Full activation of this GPCR is achieved after passing through several steps of the protein's photoactivation pathway. Key events of rhodopsin activation are the initial cis-trans photoisomerization of the covalently bound retinal moiety followed by conformational rearrangements and deprotonation of the chromophore's protonated Schiff base (PSB), which ultimately lead to full activation in the meta II state...
August 15, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28729748/on-flare-cme-characteristics-from-sun-to-earth-combining-remote-sensing-image-data-with-in-situ-measurements-supported-by-modeling
#9
Manuela Temmer, Julia K Thalmann, Karin Dissauer, Astrid M Veronig, Johannes Tschernitz, Jürgen Hinterreiter, Luciano Rodriguez
We analyze the well-observed flare and coronal mass ejection (CME) from 1 October 2011 (SOL2011-10-01T09:18) covering the complete chain of effects - from Sun to Earth - to better understand the dynamic evolution of the CME and its embedded magnetic field. We study in detail the solar surface and atmosphere associated with the flare and CME using the Solar Dynamics Observatory (SDO) and ground-based instruments. We also track the CME signature off-limb with combined extreme ultraviolet (EUV) and white-light data from the Solar Terrestrial Relations Observatory (STEREO)...
2017: Solar Physics
https://www.readbyqxmd.com/read/28716735/pupillary-measurements-and-anisocoria-in-chinese-preschoolers-3-4-years-of-age-screened-using-the-plusoptix-a12c
#10
Dan Huang, Xiaohan Zhang, Yue Wang, Hui Zhu, Hui Ding, Jing Bai, Ji Chen, Zhujun Fu, Zijin Wang, Xuejuan Chen, Hu Liu
PURPOSE: To evaluate the distribution of the pupil diameter and distance and the incidence of anisocoria in a screening setting for Chinese preschoolers 3-4 years of age. METHODS: This was a cross-sectional, population-based study conducted in children aged 3-4 years in Nanjing, China. Plusoptix photoscreening was conducted without cycloplegia. Additional assessments were conducted, including light reaction test, reevaluation for anisocoria (in dim and bright light), swinging-flashlight test, and cocaine test, if necessary...
July 14, 2017: Journal of AAPOS: the Official Publication of the American Association for Pediatric Ophthalmology and Strabismus
https://www.readbyqxmd.com/read/28711776/sleep-wake-profiles-and-circadian-rhythms-of-core-temperature-and-melatonin-in-young-people-with-affective-disorders
#11
Joanne S Carpenter, Rébecca Robillard, Daniel F Hermens, Sharon L Naismith, Christopher Gordon, Elizabeth M Scott, Ian B Hickie
While disturbances of the sleep-wake cycle are common in people with affective disorders, the characteristics of these disturbances differ greatly between individuals. This heterogeneity is likely to reflect multiple underlying pathophysiologies, with different perturbations in circadian systems contributing to the variation in sleep-wake cycle disturbances. Such disturbances may be particularly relevant in adolescents and young adults with affective disorders as circadian rhythms undergo considerable change during this key developmental period...
July 8, 2017: Journal of Psychiatric Research
https://www.readbyqxmd.com/read/28711262/genetic-and-nongenetic-factors-associated-with-milk-color-in-dairy-cows
#12
S Scarso, S McParland, G Visentin, D P Berry, A McDermott, M De Marchi
Milk color is one of the sensory properties that can influence consumer choice of one product over another and it influences the quality of processed dairy products. This study aims to quantify the cow-level genetic and nongenetic factors associated with bovine milk color traits. A total of 136,807 spectra from Irish commercial and research herds (with multiple breeds and crosses) were used. Milk lightness (Lˆ*), red-green index (aˆ*) and yellow-blue index (bˆ*) were predicted for individual milk samples using only the mid-infrared spectrum of the milk sample...
September 2017: Journal of Dairy Science
https://www.readbyqxmd.com/read/28692905/prediction-of-outcome-of-bright-light-treatment-in-patients-with-seasonal-affective-disorder-discarding-the-early-response-confirming-a-higher-atypical-balance-and-uncovering-a-higher-body-mass-index-at-baseline-as-predictors-of-endpoint-outcome
#13
Tzvetelina D Dimitrova, Gloria M Reeves, Soren Snitker, Manana Lapidus, Aamar R Sleemi, Theodora G Balis, Partam Manalai, Muhammad M Tariq, Johanna A Cabassa, Naila N Karim, Mary A Johnson, Patricia Langenberg, Kelly J Rohan, Michael Miller, John W Stiller, Teodor T Postolache
BACKGROUND: We tested the hypothesis that the early improvement in mood after the first hour of bright light treatment compared to control dim-red light would predict the outcome at six weeks of bright light treatment for depressed mood in patients with Seasonal Affective Disorder (SAD). We also analyzed the value of Body Mass Index (BMI) and atypical symptoms of depression at baseline in predicting treatment outcome. METHODS: Seventy-eight adult participants were enrolled...
November 2017: Journal of Affective Disorders
https://www.readbyqxmd.com/read/28690558/blue-enriched-white-light-enhances-physiological-arousal-but-not-behavioral-performance-during-simulated-driving-at-early-night
#14
Beatriz Rodríguez-Morilla, Juan A Madrid, Enrique Molina, Angel Correa
Vigilance usually deteriorates over prolonged driving at non-optimal times of day. Exposure to blue-enriched light has shown to enhance arousal, leading to behavioral benefits in some cognitive tasks. However, the cognitive effects of long-wavelength light have been less studied and its effects on driving performance remained to be addressed. We tested the effects of a blue-enriched white light (BWL) and a long-wavelength orange light (OL) vs. a control condition of dim light on subjective, physiological and behavioral measures at 21:45 h...
2017: Frontiers in Psychology
https://www.readbyqxmd.com/read/28676737/gene-therapy-in-a-large-animal-model-of-pde6a-retinitis-pigmentosa
#15
Freya M Mowat, Laurence M Occelli, Joshua T Bartoe, Kristen J Gervais, Ashlee R Bruewer, Janice Querubin, Astra Dinculescu, Sanford L Boye, William W Hauswirth, Simon M Petersen-Jones
Despite mutations in the rod phosphodiesterase 6-alpha (PDE6A) gene being well-recognized as a cause of human retinitis pigmentosa, no definitive treatments have been developed to treat this blinding disease. We performed a trial of retinal gene augmentation in the Pde6a mutant dog using Pde6a delivery by capsid-mutant adeno-associated virus serotype 8, previously shown to have a rapid onset of transgene expression in the canine retina. Subretinal injections were performed in 10 dogs at 29-44 days of age, and electroretinography and vision testing were performed to assess functional outcome...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28676736/lower-in-vivo-myo-inositol-in-the-anterior-cingulate-cortex-correlates-with-delayed-melatonin-rhythms-in-young-persons-with-depression
#16
Rébecca Robillard, Jim Lagopoulos, Daniel F Hermens, Sharon L Naismith, Naomi L Rogers, Django White, Joanne S Carpenter, Manreena Kaur, Elizabeth M Scott, Ian B Hickie
Myo-inositol, a second messenger glucose isomer and glial marker, is potentiated by melatonin. In addition to common abnormalities in melatonin regulation, depressive disorders have been associated with reduced myo-inositol in frontal structures. This study examined associations between myo-inositol in the anterior cingulate cortex and the timing of evening melatonin release. Forty young persons with unipolar depression were recruited from specialized mental health services (20.3 ± 3.8 years old). Healthy controls were recruited from the community (21...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28667303/measurement-of-stokes-operator-squeezing-for-continuous-variable-orbital-angular-momentum
#17
Jun Guo, Chunxiao Cai, Long Ma, Kui Liu, Hengxin Sun, Jiangrui Gao
We demonstrate experimentally a measurement scheme for the Stokes operators for the continuous-variable squeezed states of orbital angular momentum (OAM). An OAM squeezed state is generated by coupling a dim Hermite-Gauss HG01-mode quadrature-squeezed light beam with a bright HG10-mode coherent light beam on a 98/2 beam splitter. Using an asymmetric Mach-Zehnder interferometer with an extra Dove prism in one arm, we measured the three orbital Stokes operators of the OAM squeezed states with a self-homodyne detection and finally characterized their positions and noise on the orbital Poincaré sphere...
June 30, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28653274/spatial-updating-of-multiple-targets-comparison-of-younger-and-older-adults
#18
Christopher R Bennett, Jack M Loomis, Roberta L Klatzky, Nicholas A Giudice
When walking without vision, people mentally keep track of the directions and distances of previously viewed objects, a process called spatial updating. The current experiment indicates that while people across a large age range are able to update multiple targets in memory without perceptual support, aging negatively affects accuracy, precision, and decision time. Participants (20 to 80 years of age) viewed one, three, or six targets (colored lights) on the floor of a dimly lit room. Then, without vision, they walked to a target designated by color, either directly or indirectly (via a forward turning point)...
June 26, 2017: Memory & Cognition
https://www.readbyqxmd.com/read/28651468/human-adolescent-phase-response-curves-to-bright-white-light
#19
Stephanie J Crowley, Charmane I Eastman
Older adolescents are particularly vulnerable to circadian misalignment and sleep restriction, primarily due to early school start times. Light can shift the circadian system and could help attenuate circadian misalignment; however, a phase response curve (PRC) to determine the optimal time for receiving light and avoiding light is not available for adolescents. We constructed light PRCs for late pubertal to postpubertal adolescents aged 14 to 17 years. Participants completed 2 counterbalanced 5-day laboratory sessions after 8 or 9 days of scheduled sleep at home...
June 1, 2017: Journal of Biological Rhythms
https://www.readbyqxmd.com/read/28644985/depressive-like-behavior-is-elevated-among-offspring-of-parents-exposed-to-dim-light-at-night-prior-to-mating
#20
Yasmine M Cissé, Kathryn L G Russart, Randy J Nelson
Rates of major depressive disorder (MDD) have steadily increased over the past 50 years. Many factors have been implicated in the etiology of depressive disorders and environmental influences are being increasingly recognized. The increase in depression rates has coincided with increased artificial nighttime lighting. Exposure to light at night (LAN) has been associated with increased depressive-like behavior in rodents and decreased mood in humans. However, relatively little is known on the multigenerational effects of dLAN on affect...
September 2017: Psychoneuroendocrinology
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