SCN organization reconsidered.

abstract：:Endogenous circadian rhythms are involved in various photoperiodic responses of birds. Investigations involving the mechanisms of photoperiodic time measurement in birds have been confined mainly to temperate zone species using males exclusively. Due to the paucity of experimental evidence on subtropical birds that ha...

journal_title：Journal of biological rhythms

authors： Ravikumar G,Senthilkumaran B,Tewary PD,Goel AK

更新日期：1995-12-01 00:00:00

abstract：:The mammalian endogenous circadian clock, the suprachiasmatic nuclei, receives environmental inputs, namely the light-dark cycle, through photopigments located in the eye and from melanopsin-expressing retinal ganglion cells. The authors investigated the influence of light wavelength and intensity on the synchronizati...

journal_title：Journal of biological rhythms

authors： Perret M,Gomez D,Barbosa A,Aujard F,Théry M

更新日期：2010-06-01 00:00:00

abstract：:The circadian clock controls 24-h biological rhythms in our body, influencing many time-related activities such as sleep and wake. The simplest circadian clock is found in cyanobacteria, with the proteins KaiA, KaiB, and KaiC generating a self-sustained circadian oscillation of KaiC phosphorylation and dephosphorylati...

journal_title：Journal of biological rhythms

authors： Jeong YM,Dias C,Diekman C,Brochon H,Kim P,Kaur M,Kim YS,Jang HI,Kim YI

更新日期：2019-08-01 00:00:00

abstract：:The authors sought to investigate the role of phytochromes A and B (phyA and phyB) and cryptochromes 1 and 2 (cryl and cry2) in the synchronization of the leaf position rhythm in Arabidopsis thaliana. The seedlings were transferred from white light-dark cycles to free-running conditions with or without exposure to a l...

journal_title：Journal of biological rhythms

authors： Yanovsky MJ,Mazzella MA,Whitelam GC,Casal JJ

更新日期：2001-12-01 00:00:00

abstract：:Social jetlag represents the discrepancy between circadian and social clocks, which is measured as the difference in hours in midpoint of sleep between work days and free days. Previous studies have shown social jetlag to be associated with body mass index (BMI), glycated hemoglobin levels, heart rate, depressive symp...

journal_title：Journal of biological rhythms

authors： Rutters F,Lemmens SG,Adam TC,Bremmer MA,Elders PJ,Nijpels G,Dekker JM

更新日期：2014-10-01 00:00:00

abstract：:Siberian hamsters transferred from a long (16 h light/day [16 L]) to an intermediate (13.5 L) day length (DL) undergo testicular regression within 2 months followed approximately 2 months later by "spontaneous" testicular recrudescence. Recovery of gonadal function after prolonged exposure to intermediate DLs is thoug...

journal_title：Journal of biological rhythms

authors： Kauffman AS,Zucker I

更新日期：2002-08-01 00:00:00

abstract：:Little is known about the differences in the neural substrates of circadian rhythms that are responsible for the maintenance of differences between diurnal and nocturnal patterns of activity in mammals. In both groups of animals, the suprachiasmatic nucleus (SCN) functions as the principal circadian pacemaker, and sur...

journal_title：Journal of biological rhythms

authors： Nunez AA,Bult A,McElhinny TL,Smale L

更新日期：1999-08-01 00:00:00

abstract：:The role of the intergeniculate leaflet of the thalamus (IGL) in photoperiod responsiveness was examined in a laboratory-selected line of photoperiod nonresponsive (NR) Siberian hamsters. NR hamsters fail to exhibit typical winter-type responses (i.e., gonadal regression and development of winter-type pelage) when exp...

journal_title：Journal of biological rhythms

authors： Freeman DA,Teubner BJ,Goldman BD

更新日期：2006-06-01 00:00:00

abstract：:The hypothalamic suprachiasmatic nucleus (SCN), a circadian pacemaker, is present in all mammalian brains. It has a complex organization of peptide-containing neurons that is similar among species, but calcium-binding proteins are expressed variably. Neurons containing calretinin have been described in the SCN in a nu...

journal_title：Journal of biological rhythms

authors： Moore RY

更新日期：2016-08-01 00:00:00

abstract：:A single light episode during the first larval stage can set the phase of adult Drosophila activity rhythms, showing that a light-sensitive circadian clock is functional in larvae and is capable of keeping time throughout development. These behavioral data are supported by the finding that neurons expressing clock pro...

journal_title：Journal of biological rhythms

authors： Malpel S,Klarsfeld A,Rouyer F

更新日期：2004-02-01 00:00:00

abstract：:Photic signals affect circadian activity rhythms by both phasic and tonic mechanisms that modulate pacemaker phase and period. In mammals, the effects of light on circadian activity are mediated by the retina, which communicates with the suprahiasmatic nucleus (SCN) by two different anatomical routes: the retino-hypot...

journal_title：Journal of biological rhythms

authors： Pickard GE,Ralph MR,Menaker M

更新日期：1987-04-01 00:00:00

abstract：:Various aspects of mammalian endocrine physiology show a time-of-day variation with a period of 24 h, which represents an adaptation to the daily environmental fluctuations resulting from the rotation of the earth. These 24-h rhythms in hormone abundance and consequently hormone function may rely on rhythmic signals p...

journal_title：Journal of biological rhythms

authors： Lin XW,Blum ID,Storch KF

更新日期：2015-08-01 00:00:00

abstract：:In isolated slices of hypothalamus, suprachiasmatic nucleus (SCN) neurons were recorded intracellularly. Blockade of Ca++ channels increased spike duration, eliminating an early component of the afterhyperpolarization (AHP) that followed evoked spikes. The duration and reversal potential of AHPs were, however, unaffec...

journal_title：Journal of biological rhythms

authors： Thomson AM,West DC

更新日期：1990-04-01 00:00:00

abstract：:The aim of this study was to replicate and extend previous work in which the authors observed lower, shorter, and advanced nocturnal melatonin secretion patterns in premenstrually depressed patients compared to those in healthy control women. The authors also sought to test the hypothesis that the therapeutic effect o...

journal_title：Journal of biological rhythms

authors： Parry BL,Berga SL,Mostofi N,Klauber MR,Resnick A

更新日期：1997-02-01 00:00:00

abstract：:Photoreception in the mammalian retina is not restricted to rods and cones but extends to a small number of intrinsically photosensitive retinal ganglion cells expressing the photopigment melanopsin. These mRGCs are especially important contributors to circadian entrainment, the pupil light reflex, and other so-called...

journal_title：Journal of biological rhythms

authors： Enezi Ja,Revell V,Brown T,Wynne J,Schlangen L,Lucas R

更新日期：2011-08-01 00:00:00

abstract：:In our attempts to understand the circadian system, we unavoidably rely on abstractions. Instead of describing the behavior of the circadian system in all its complexity, we try to derive basic features from which we form a global concept on how the system works. Such a basic concept is a model of reality. The author ...

journal_title：Journal of biological rhythms

authors： Beersma DG

更新日期：2005-08-01 00:00:00

abstract：:Many mammalian cell types show daily rhythms in gene expression driven by a circadian pacemaker. For example, cultured astrocytes display circadian rhythms in Period1 and Period2 expression. It is not known, however, how or which intercellular factors synchronize and sustain rhythmicity in astrocytes. Because astrocyt...

journal_title：Journal of biological rhythms

authors： Marpegan L,Krall TJ,Herzog ED

更新日期：2009-04-01 00:00:00

abstract：:To assess binocular interactions and possible ocular dominance in entrainment of circadian rhythms, Syrian hamsters maintained in LL were subjected for several weeks to schedules of eye occlusion with opaque contact lenses. In separate groups, the opaque lens was inserted into the left or right eye for 12 h at the sam...

journal_title：Journal of biological rhythms

authors： Park JH,Paul MJ,Butler MP,Zucker I

更新日期：2005-02-01 00:00:00

abstract：:Two major approaches have been used to model circadian clocks. Qualitative modeling, used prior to the recent wealth of detailed molecular knowledge, makes general predictions but cannot provide detailed mechanistic insights. The more recent biophysical approach, on the other hand, incorporates the biochemical events ...

journal_title：Journal of biological rhythms

authors： Forger D,Gonze D,Virshup D,Welsh DK

更新日期：2007-06-01 00:00:00

abstract：:Several authors have suggested that the transcriptional regulatory protein c-Fos might be part of the mechanism for photic entrainment of the circadian pacemaker in the suprachiasmatic nucleus (SCN) to environmental light:dark cycles. This hypothesis has been based on evidence gathered using single light pulses admini...

journal_title：Journal of biological rhythms

authors： Schwartz WJ,Peters RV,Aronin N,Bennett MR

更新日期：1996-03-01 00:00:00

abstract：:Temperature compensation and period determination by casein kinase 1 (CK1) are conserved features of eukaryotic circadian rhythms, whereas the clock gene transcription factors that facilitate daily gene expression rhythms differ between phylogenetic kingdoms. Human red blood cells (RBCs) exhibit temperature-compensate...

journal_title：Journal of biological rhythms

authors： Beale AD,Kruchek E,Kitcatt SJ,Henslee EA,Parry JSW,Braun G,Jabr R,von Schantz M,O'Neill JS,Labeed FH

更新日期：2019-04-01 00:00:00

abstract：:Despite the omnipresence of artificial and natural light exposure, there exists little guidance in the United States and elsewhere on light exposure in terms of timing, intensity, spectrum, and other light characteristics known to affect human health, performance, and well-being; in parallel, there is little informati...

journal_title：Journal of biological rhythms

authors： Mason IC,Boubekri M,Figueiro MG,Hasler BP,Hattar S,Hill SM,Nelson RJ,Sharkey KM,Wright KP,Boyd WA,Brown MK,Laposky AD,Twery MJ,Zee PC

更新日期：2018-10-01 00:00:00

abstract：:Reduced sensitivity to short-wavelength (blue) light with age has been shown for light-induced melatonin suppression. The current research aimed to determine if a similar age-related reduction occurs in subjective alertness, mood, and circadian phase-advancing responses. Young (n = 11, 23.0 +/- 2.9 years) and older (n...

journal_title：Journal of biological rhythms

authors： Sletten TL,Revell VL,Middleton B,Lederle KA,Skene DJ

更新日期：2009-02-01 00:00:00

abstract：:Hibernating animals have been a successful model system for elucidating fundamental properties of many physiological systems. Over the past 50 years, a diverse literature has emerged on the role of the circadian system in control and expression of winter torpor in several orders of birds and mammals. This body of rese...

journal_title：Journal of biological rhythms

authors： Ruby NF

更新日期：2003-08-01 00:00:00

abstract：:A gradual adaptation to a shifted light-dark (LD) cycle is a key element of the circadian clock system and believed to be controlled by the central circadian pacemaker, the suprachiasmatic nucleus (SCN). Endocrine factors have a strong influence on the regulation of the circadian clock network and alter acute photic r...

journal_title：Journal of biological rhythms

authors： Pilorz V,Kolms B,Oster H

更新日期：2020-12-01 00:00:00

abstract：:The suprachiasmatic nucleus (SCN) drives and synchronizes daily rhythms at the cellular level via transcriptional-translational feedback loops comprising clock genes such as Bmal1 and Period (Per). Glycogen synthase kinase 3 (GSK3), a serine/threonine kinase, phosphorylates at least 5 core clock proteins and shows diu...

journal_title：Journal of biological rhythms

authors： Besing RC,Paul JR,Hablitz LM,Rogers CO,Johnson RL,Young ME,Gamble KL

更新日期：2015-04-01 00:00:00

abstract：:In many animals, the circadian clock plays a role in adapting to the coming season by measuring day length. The mechanism for measuring day length and its neuronal circuits remains elusive, however. Under laboratory conditions, the fruit fly, Drosophila melanogaster, displays 2 activity peaks: one in the morning and o...

journal_title：Journal of biological rhythms

authors： Kistenpfennig C,Nakayama M,Nihara R,Tomioka K,Helfrich-Förster C,Yoshii T

更新日期：2018-02-01 00:00:00

abstract：:A physiologically based mathematical model of a putative sleep-wake regulatory network is used to investigate the transition from typical human sleep patterns to spontaneous internal desynchrony behavior observed under temporal isolation conditions. The model sleep-wake regulatory network describes the neurotransmitte...

journal_title：Journal of biological rhythms

authors： Gleit RD,Diniz Behn CG,Booth V

更新日期：2013-10-01 00:00:00

abstract：:The pineal organ of the lizard Anolis carolinensis acts as a transducer of photoperiodic information, since light can affect the pineal melatonin rhythm (PMR). The synthesis and secretion of melatonin may be a major mechanism whereby a circadian pacemaker within the pineal can control circadian clocks located elsewher...

journal_title：Journal of biological rhythms

authors： Underwood H,Calaban M

更新日期：1987-10-01 00:00:00

abstract：:Seasonal changes in numerous aspects of mammalian immune function arise as a result of the annual variation in environmental day length (photoperiod), but it is not known if absolute photoperiod or relative change in photoperiod drives these changes. This experiment tested the hypothesis that an individual's history o...

journal_title：Journal of biological rhythms

authors： Prendergast BJ,Pyter LM

更新日期：2009-12-01 00:00:00