Circadian Clocks in the Hematologic System.

abstract：:How the cellular elements of the SCN are synchronized to each other is not well understood. We explore circadian oscillations manifest at the level of the cell, the tissue, and the whole animal to better understand intra-SCN synchrony and master clock function of the nucleus. At each level of analysis, responses to va...

journal_title：Journal of biological rhythms

authors： Butler MP,Silver R

更新日期：2009-10-01 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：:A recent report that popliteal illumination shifted the circadian rhythms of body temperature and melatonin challenged the longstanding belief that light phase-shifting the circadian system in mammals is mediated only through the retina. The authors tested effects of popliteal illumination and illumination provided th...

journal_title：Journal of biological rhythms

authors： Jean-Louis G,Kripke DF,Cole RJ,Elliot JA

更新日期：2000-06-01 00:00:00

abstract：:Rats anticipate a fixed daily feeding time by entrainment of a component of their multioscillatory circadian system. The range of stimuli capable of entraining this component is little studied. Previous studies suggest that restricted water access is not an effective entrainment stimulus, as measured by general locomo...

journal_title：Journal of biological rhythms

authors： Mistlberger RE

更新日期：1992-07-01 00:00:00

abstract：:An understanding of the retinal mechanisms in mammalian photoentrainment will greatly facilitate optimization of the wavelength, intensity, and duration of phototherapeutic treatments designed to phase shift endogenous biological rhythms. A small population of widely dispersed retinal ganglion cells projecting to the ...

journal_title：Journal of biological rhythms

authors： Rollag MD,Berson DM,Provencio I

更新日期：2003-06-01 00:00:00

abstract：:Previous research has demonstrated a clear link between late chronotype and depression. The vulnerability factors underpinning this link, however, are unclear. Here the relationship between two specific emotion regulation strategies, cognitive reappraisal and expressive suppression, and chronotype was investigated usi...

journal_title：Journal of biological rhythms

authors： Watts AL,Norbury R

更新日期：2017-08-01 00:00:00

abstract：:The mammalian circadian clock in the suprachiasmatic nucleus (SCN) drives and maintains 24-h physiological rhythms, the phases of which are set by the local environmental light-dark cycle. Gastrin-releasing peptide (GRP) communicates photic phase setting signals in the SCN by increasing neurophysiological activity of ...

journal_title：Journal of biological rhythms

authors： Gamble KL,Kudo T,Colwell CS,McMahon DG

更新日期：2011-04-01 00:00:00

abstract：:Almost exclusively, photoperiodic insects respond to a given photoperiod in one of two ways: a "long-day" response or a "short-day" response. Intermediate responses occur only at a very restricted range of photoperiods (often less than 30 min) and are generally population phenomena rather than intermediate responses o...

journal_title：Journal of biological rhythms

authors： Wassmer GT,Page TL

更新日期：1993-04-01 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：:The circadian rhythm of eclosion activity and its pacemaker were analyzed in a series of latitudinal races of Drosophila auraria ranging from 34.2 degrees to 42.9 degrees N in Japan. The phase of the rhythm (psi EL) to the daily photoperiod (PP) changes as daylength is increased, and the slope of psi EL (PP) changes w...

journal_title：Journal of biological rhythms

authors： Pittendrigh CS,Takamura T

更新日期：1989-07-01 00:00:00

abstract：:The tau mutation in Syrian hamsters (Mesocricetus auratus) is phenotypically expressed in a period of the circadian rhythm of about 20 h in homozygotes (SS) and about 22 h in heterozygotes (S+). The authors investigate whether this well-defined model for variation in circadian period exhibits associated changes in ene...

journal_title：Journal of biological rhythms

authors： Oklejewicz M,Hut RA,Daan S,Loudon AS,Stirland AJ

更新日期：1997-10-01 00:00:00

abstract：:Since the advent of techniques to investigate gene expression on a large scale, numerous circadian rhythms in mRNA amount have been reported. These rhythms generally differ in amplitude and phase. The authors investigated how far a parameter not regulated by the circadian clock can influence the phase of a rhythm in R...

journal_title：Journal of biological rhythms

authors： Jacobshagen S,Kessler B,Rinehart CA

更新日期：2008-12-01 00:00:00

abstract：:Male rose-ringed parakeets (Psittacula krameri) were transferred to a long photoperiod (LP; LD 16:8) or a short photoperiod (SP; LD 8:16) for 45 or 90 days on four dates corresponding to the beginnings of different reproductive phases in an annual testicular cycle, and testicular responsiveness was evaluated by compar...

journal_title：Journal of biological rhythms

authors： Maitra SK,Dey M

更新日期：1992-04-01 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：:Past research has shown that there is a circadian oscillator in laboratory rats that is entrained by restricted feeding schedules. However, in laboratory rats at least, the light-dark (LD) cycle is the dominant zeitgeber in the entrainment of wheel-running activity rhythms. Given that dasyurid marsupials are predomina...

journal_title：Journal of biological rhythms

authors： Coleman GJ,O'Reilly HM,Armstrong SM

更新日期：1989-04-01 00:00:00

abstract：:The SCN has long had organizational schemas imposed on it. In most, the SCN is dichotomized, with one region typically associated with the presence of vasopressin cells and the other associated with cells containing vasoactive intestinal polypeptide and certain afferent terminal fields. If assumed to be accurate, the ...

journal_title：Journal of biological rhythms

authors： Morin LP

更新日期：2007-02-01 00:00:00

abstract：:Aging alters numerous aspects of circadian biology, including the amplitude of rhythms generated by the suprachiasmatic nuclei (SCN) of the hypothalamus, the site of the central circadian pacemaker in mammals, and the response of the pacemaker to environmental stimuli such as light. Although previous studies have desc...

journal_title：Journal of biological rhythms

authors： Kolker DE,Fukuyama H,Huang DS,Takahashi JS,Horton TH,Turek FW

更新日期：2003-04-01 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：:Testicular growth was monitored in male ferrets subjected to one of the following photoperiodic treatments begun at weaning (8 weeks of age): 8 hr light/day (short days), 18 hr light/day (long days), or short days followed by transition to long days at either 10, 12, or 14 weeks of age. Mean ages to achieve adult test...

journal_title：Journal of biological rhythms

authors： Sisk CL

更新日期：1990-10-01 00:00:00

abstract：:Honey bee (Apis mellifera) workers emerge from the pupae with no circadian rhythms in behavior or brain clock gene expression but show strong rhythms later in life. This postembryonic development of circadian rhythms is reminiscent of that of infants of humans and other primates but contrasts with most insects, which ...

journal_title：Journal of biological rhythms

authors： Eban-Rothschild A,Shemesh Y,Bloch G

更新日期：2012-06-01 00:00:00

abstract：:Casein kinase 1ε (CK1ε) performs key phosphorylation reactions in the circadian clock mechanism that determine period. We show that the central clock protein PERIOD2 (PER2) not only acts as a transcriptional repressor but also inhibits the autoinactivation of CK1ε, thereby promoting CK1ε activity. Moreover, PER2 recip...

journal_title：Journal of biological rhythms

authors： Qin X,Mori T,Zhang Y,Johnson CH

更新日期：2015-06-01 00:00:00

abstract：:The purpose of this study was to determine whether decreased day lengths affect reproduction or the immune system in inbred mice. Irrespective of a nocturnal pineal melatonin rise, the signal for day length information, body and testis weights were the same in various strains 8 weeks after transfer from long to short ...

journal_title：Journal of biological rhythms

authors： Yellon SM,Tran LT

更新日期：2002-02-01 00:00:00

abstract：:An outstanding unresolved issue in chronobiology is how the level of locomotor activity influences length of the free-running, endogenous circadian period (tau). To address this issue, the authors studied a novel model, 4 replicate lines of laboratory house mice (Mus domesticus) that had been selectively bred for high...

journal_title：Journal of biological rhythms

authors： Koteja P,Swallow JG,Carter PA,Garland T Jr

更新日期：2003-12-01 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：: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：: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：:Although pineal "synaptic" ribbons (SR) are frequently examined by means of quantitative electron microscopy, their functional significance remains unclear. The same is true for related structures--"synaptic" spherules (SPH). In the course of such studies, it has been noted that SR counts may differ from laboratory to...

journal_title：Journal of biological rhythms

authors： Karasek M,Lewinski A,Vollrath L

更新日期：1988-04-01 00:00:00

abstract：:Numerous studies have used the classic van der Pol oscillator, which contains a cubic nonlinearity, to model the effect of light on the human circadian pacemaker. Jewett and Kronauer demonstrated that Aschoff's rule could be incorporated into van der Pol type models and used a van der Pol type oscillator with higher o...

journal_title：Journal of biological rhythms

authors： Forger DB,Jewett ME,Kronauer RE

更新日期：1999-12-01 00:00:00

abstract：:Temperature compensation of circadian rhythms in neuronal firing rate was investigated in the suprachiasmatic nucleus (SCN) of ground squirrels and rats in vitro. A reduction in SCN temperature from 37 to 25 degrees C reduced peak firing rates by > 70% in rats but only by approximately 21% in squirrels; trough firing ...

journal_title：Journal of biological rhythms

authors： Ruby NF,Heller HC

更新日期：1996-06-01 00:00:00

abstract：:Most cyclic biological processes are under control of a circadian molecular timing system that synchronizes these phenomena to the 24-h day. One generic property of circadian-controlled processes is that they operate within a specific temperature range, below which the manifestation of rhythm ceases. Little is known a...

journal_title：Journal of biological rhythms

authors： Maguire SE,Schmidt PS,Sehgal A

更新日期：2014-06-01 00:00:00