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Phase angle circadian

D G Gubin, Т N Malishevskaya, Y S Astakhov, S Y Astakhov, G Cornelissen, V A Kuznetsov, D Weinert
Advanced primary open-angle glaucoma (POAG) is characterized by progressive retinal ganglion cell complex (RGCC) damage that may cause subsequent disruption of the circadian rhythms. Therefore, we evaluated circadian body temperature (BT) rhythm and sleep characteristics of 115 individuals (38 men and 77 women) diagnosed with POAG. GLV (global loss volume; %), a measure of RGCC damage, was estimated by high-definition optical coherence tomography, and RGC functional ability was assessed by pattern electroretinogram amplitude (PERGA)...
January 21, 2019: Chronobiology International
Stacey L Simon, Cecilia Diniz Behn, Melanie Cree-Green, Jill L Kaar, Laura Pyle, Stephen M M Hawkins, Haseeb Rahat, Yesenia Garcia-Reyes, Kenneth P Wright, Kristen J Nadeau
OBJECTIVES: To examine the relationship between insulin resistance (IR) and sleep/circadian health in overweight/obese adolescents. We hypothesized that insufficient and delayed sleep would be associated with IR in this population. STUDY DESIGN: Thirty-one adolescents (mean age, 16.0 ± 1.4 years; 77% female) with body mass index ≥90th percentile for age/sex were recruited from outpatient clinics at a children's hospital. Participants underwent 1 week of objective home sleep monitoring with wrist actigraphy during the academic year...
November 19, 2018: Journal of Pediatrics
Barbara L Parry, Charles J Meliska, Ana M Lopez, Diane L Sorenson, L Fernando Martinez, Henry J Orff, Richard L Hauger, Daniel F Kripke
BACKGROUND: Peripartum major depression (MD) disables mothers and impairs emotional and neurocognitive development of offspring. We tested the hypothesis that critically-timed wake therapy (WT) relieves peripartum MD by altering melatonin and sleep timing, differentially, in antepartum vs. postpartum depressed patients (DP). METHODS: In a university clinical research center, we initially randomized 50 women - 26 antepartum (17 healthy comparison-HC, 9 DP) and 24 postpartum (8 HC, 16 DP) - to a cross-over trial of one night of early-night wake therapy (EWT: sleep 3:00-7:00 am) vs...
November 5, 2018: Journal of Affective Disorders
T Woelders, E J Wams, M C M Gordijn, D G M Beersma, R A Hut
The mammalian circadian system encodes both absolute levels of light intensity and color to phase-lock (entrain) its rhythm to the 24-h solar cycle. The evolutionary benefits of circadian color-coding over intensity-coding per se are yet far from understood. A detailed characterization of sunlight is crucial in understanding how and why circadian photoreception integrates color and intensity information. To this end, we continuously measured 100 days of sunlight spectra over the course of a year. Our analyses suggest that circadian color-coding may have evolved to cope with cloud-induced variation in light intensity...
October 12, 2018: Scientific Reports
Kelin L Wheaton, Katelin F Hansen, Sydney Aten, Kyle A Sullivan, Hyojung Yoon, Kari R Hoyt, Karl Obrietan
Within the suprachiasmatic nucleus (SCN)-the locus of the master circadian clock- transcriptional regulation via the CREB/CRE pathway is implicated in the functioning of the molecular clock timing process, and is a key conduit through which photic input entrains the oscillator. One event driving CRE-mediated transcription is the phosphorylation of CREB at serine 133 (Ser133 ). Indeed, numerous reporter gene assays have shown that an alanine point mutation in Ser133 reduces CREB-mediated transcription. Here, we sought to examine the contribution of Ser133 phosphorylation to the functional role of CREB in SCN clock physiology in vivo...
September 3, 2018: Journal of Biological Rhythms
Martina Pfeffer, Zuzana Zimmermann, Suzana Gispert, Georg Auburger, Horst-Werner Korf, Charlotte von Gall
Parkinson's disease (PD) is characterized by distinct motor and non-motor symptoms. Sleep disorders are the most frequent and challenging non-motor symptoms in PD patients, and there is growing evidence that they are a consequence of disruptions within the circadian system. PD is characterized by a progressive degeneration of the dorsal vagal nucleus and midbrain dopaminergic neurons together with an imbalance of many other neurotransmitters. Mutations in α-synuclein (SNCA), a protein modulating SNARE complex-dependent neurotransmission, trigger dominantly inherited PD variants and sporadic cases of PD...
June 3, 2018: International Journal of Molecular Sciences
Daniel Janik, Justin Frey
Most work looking at nonphotic effects on circadian rhythms is conducted when animals are held under freerunning conditions, usually constant darkness. However, for nonphotic effects to be functionally significant, they should be demonstrable under conditions in which most animals live, i.e., a 24-hr light-dark cycle (LD). Syrian hamsters held in LD 6:18 were administered nonphotic stimulation in the form of a 3-hr confinement to a novel wheel starting about 6 hr before the start of their normal nightly activity bout...
September 2018: Chronobiology International
Jason C Ong, Hannah L Taylor, Margaret Park, Helen J Burgess, Rina S Fox, Sarah Snyder, Jeanetta C Rains, Colin A Espie, James K Wyatt
OBJECTIVE: This observational pilot study examined objective circadian phase and sleep timing in chronic migraine (CM) and healthy controls (HC) and the impact of circadian factors on migraine frequency and severity. BACKGROUND: Sleep disturbance has been identified as a risk factor in the development and maintenance of CM but the biological mechanisms linking sleep and migraine remain largely theoretical. METHODS: Twenty women with CM and 20 age-matched HC completed a protocol that included a 7 day sleep assessment at home using wrist actigraphy followed by a circadian phase assessment using salivary melatonin...
July 2018: Headache
Roneil G Malkani, Sabra M Abbott, Kathryn J Reid, Phyllis C Zee
STUDY OBJECTIVES: To report the diagnostic and treatment challenges of sighted non-24-hour sleep-wake disorder (N24SWD). METHODS: We report a series of seven sighted patients with N24SWD clinically evaluated by history and sleep diaries, and when available wrist actigraphy and salivary melatonin levels, and treated with timed melatonin and bright light therapy. RESULTS: Most patients had a history of a delayed sleep-wake pattern prior to developing N24SWD...
April 15, 2018: Journal of Clinical Sleep Medicine: JCSM: Official Publication of the American Academy of Sleep Medicine
Zoélia Camila Moura Bessa, Paula Rocha De Melo, Bruno S B Gonçalves, Carolina V M De Azevedo
In marmosets, social synchrony between circadian profiles of activity is stronger in animals that cohabit in a family. The activity of three breeding pairs was recorded by actiwatches to investigate the mechanisms involved in the synchrony between the circadian activity profiles during cohabitation in marmoset reproductive pairs. The dyads were submitted to LD 12:12 (21 days) and LL: 1) cohabitation (24 days), 2) removal of the cage mate (20 days), 3) reintroduction of the mate into the cage of the 1st situation (30 days) and 4) removal of the cage mate (7 days)...
May 2018: Chronobiology International
José M Duhart, Lucila Brocardo, Carlos S Caldart, Luciano Marpegan, Diego A Golombek
The mammalian circadian system is controlled by a central oscillator located in the suprachiasmatic nuclei (SCN) of the hypothalamus, in which glia appears to play a prominent role. Gliomas originate from glial cells and are the primary brain tumors with the highest incidence and mortality. Optic pathway/hypothalamic gliomas account for 4-7% of all pediatric intracranial tumors. Given the anatomical location, which compromises both the circadian pacemaker and its photic input pathway, we decided to study whether the presence of gliomas in the hypothalamic region could alter circadian behavioral outputs...
2017: Frontiers in Physiology
Thomas Kantermann, Charmane I Eastman
The timing of the circadian clock, circadian period and chronotype varies among individuals. To date, not much is known about how these parameters vary over time in an individual. We performed an analysis of the following five common circadian clock and chronotype measures: 1) the dim light melatonin onset (DLMO, a measure of circadian phase), 2) phase angle of entrainment (the phase the circadian clock assumes within the 24-h day, measured here as the interval between DLMO and bedtime/dark onset), 3) free-running circadian period (tau) from an ultradian forced desynchrony protocol (tau influences circadian phase and phase angle of entrainment), 4) mid-sleep on work-free days (MSF from the Munich ChronoType Questionnaire; MCTQ) and 5) the score from the Morningness-Eveningness Questionnaire (MEQ)...
February 2018: Chronobiology International
Natalia Madrid-López, Jorge Estrada, Javier Díaz, Alejandro Bassi, Paul H Délano, Adrián Ocampo-Garcés
There is a neural matrix controlling the sleep-wake cycle (SWC) embedded within high ranking integrative mechanisms in the central nervous system. Nicotinic alpha-9 acetylcholine receptor subunit (alpha-9 nAChR) participate in physiological processes occurring in sensory, endocrine and immune systems. There is a relationship between the SWC architecture, body homeostasis and sensory afferents so that disruption of afferent signaling is expected to affect the temporal organization of sleep and wake states. The analysis of the SWC of 9 nAChR knock-out animals may help to reveal the contribution of alpha-9 nAChR to sleep chronobiological determinants...
2017: Frontiers in Cellular Neuroscience
Jhenkruthi Vijaya Shankara, Angélique Orr, Richelle Mychasiuk, Michael C Antle
The mammalian circadian clock is synchronized to the day : night cycle by light. Serotonin modulates the circadian effects of light, with agonists inhibiting response to light and antagonists enhancing responses to light. A special class of serotonergic compounds, the mixed 5-HT1A agonist/antagonists, potentiates light-induced phase advances by up to 400% when administered acutely. In this study, we examine the effects of one of these mixed 5-HT1A agonist/antagonists, BMY7378, when administered chronically...
December 2017: European Journal of Neuroscience
Erin E Flynn-Evans, Julia A Shekleton, Belinda Miller, Lawrence J Epstein, Douglas Kirsch, Lauren A Brogna, Liza M Burke, Erin Bremer, Jade M Murray, Philip Gehrman, Shantha M W Rajaratnam, Steven W Lockley
Objectives: We aimed to identify the prevalence of circadian phase and phase angle abnormalities in patients with insomnia. Methods: We conducted a cross-sectional, multicenter study at three sleep laboratories in the United States and Australia. Patients with insomnia and healthy control participants completed a sleep log for 7 days. Circadian phase was assessed from salivary dim light melatonin onset (DLMO) time during a 12-hour laboratory visit. Results: Seventy-nine patients meeting the Research Diagnostic Criteria for Primary, Psychophysiological, Paradoxical, and/or Idiopathic Childhood Insomnia (46 females, 35...
December 1, 2017: Sleep
L Beck
The locomotor activity of the exclusively dark-active species Admetus pumilio shows a bigeminal type of diurnal rhythm, modified by an interposed third peak of activity. In accordance with Aschoff's rule, the period length depends on light intensity and is shortened in DD. The phase-angle difference must be determined separately for each form of activity. The first movements at the resting place ("awakening") and departure from it are the most readily identifiable forms of activity. Awakening takes place earlier and earlier with decreasing light intensity, thus diverging from departure more and more...
March 1972: Oecologia
Leslie M Swanson, Helen J Burgess, Edward D Huntley, Holli Bertram, Ann Mooney, Jennifer Zollars, Richard Dopp, Robert Hoffmann, Roseanne Armitage, J Todd Arnedt
Few studies have examined relationships between circadian rhythms and unipolar major depressive disorder. Further, no study to date has examined circadian markers as predictors of response to depression treatment. In the present study, we examined associations between circadian timing and its alignment with sleep and depression severity in 30 adults with major depressive disorder who completed a randomized controlled trial of two weeks of time in bed (TIB) restriction administered adjunctive to fluoxetine, with a focus on sex differences...
June 2017: Psychiatry Research
Veronica Akle, Alexander J Stankiewicz, Vasili Kharchenko, Lili Yu, Peter V Kharchenko, Irina V Zhdanova
The circadian system may regulate adult neurogenesis via intracellular molecular clock mechanisms or by modifying the environment of neurogenic niches, with daily variation in growth factors or nutrients depending on the animal's diurnal or nocturnal lifestyle. In a diurnal vertebrate, zebrafish, we studied circadian distribution of immunohistochemical markers of the cell division cycle (CDC) in 5 of the 16 neurogenic niches of adult brain, the dorsal telencephalon, habenula, preoptic area, hypothalamus, and cerebellum...
February 15, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Joanne S Carpenter, Amy C Abelmann, Sean N Hatton, Rébecca Robillard, Daniel F Hermens, Maxwell R Bennett, Jim Lagopoulos, Ian B Hickie
Affective disorders in young people have been associated with disruptions in circadian rhythms, including abnormalities in secretion of the pineal hormone melatonin. Previous research reports relationships between pineal gland volumes, melatonin secretion, and sleep-wake cycles, but the relationship between these factors has not been explored in affective disorders. This study aimed to characterize these factors and explore associations with mood symptoms and functioning in a sample of young people with affective disorders...
December 2017: Brain Imaging and Behavior
K G Baron, K J Reid, T Kim, L Van Horn, H Attarian, L Wolfe, J Siddique, G Santostasi, P C Zee
INTRODUCTION: Disruption of circadian rhythms is one of the proposed mechanisms linking late sleep timing to obesity risk but few studies have evaluated biological markers outside of the laboratory. The goal of this study was to determine the relationship between the timing and alignment of melatonin and sleep onset (phase angle) with body mass index (BMI), body fat and obesity-related behaviors. We hypothesized that circadian alignment (relationship of melatonin to sleep timing) rather than circadian (melatonin) timing would be associated with higher BMI, body fat, dietary intake and lower physical activity...
February 2017: International Journal of Obesity: Journal of the International Association for the Study of Obesity
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