Clocks within the Master Gland: Hypophyseal Rhythms and Their Physiological Significance.

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：:Life in the Arctic presents organisms with multiple challenges, including extreme photic conditions, cold temperatures, and annual loss and daily movement of sea ice. Polar bears (Ursus maritimus) evolved under these unique conditions, where they rely on ice to hunt their main prey, seals. However, very little is know...

journal_title：Journal of biological rhythms

authors： Ware JV,Rode KD,Robbins CT,Leise T,Weil CR,Jansen HT

更新日期：2020-04-01 00:00:00

abstract：:Groups of Syrian hamsters were exposed to LD cycles with twilight transitions and photoperiods simulating natural lighting conditions at the summer solstice (SS), equinox, and winter solstice (WS) at 41 degrees N and at the winter solstice at the Arctic Circle (WS 66 degrees N) but with daytime illuminance truncated a...

journal_title：Journal of biological rhythms

authors： Boulos Z,Macchi MM

更新日期：2005-04-01 00:00:00

abstract：:Sleep disturbances are an all-too-familiar symptom of jet lag and a prime source of complaints for transmeridian travelers and flight crews alike. They are the result of a temporary loss of synchrony between an abruptly shifted sleep period, timed in accordance with the new local day-night cycle, and a gradually reent...

journal_title：Journal of biological rhythms

authors： Boulos Z,Campbell SS,Lewy AJ,Terman M,Dijk DJ,Eastman CI

更新日期：1995-06-01 00:00:00

abstract：:Female Drosophila melanogaster, like many other organisms, exhibit different behavioral repertoires after mating with a male. These postmating responses (PMRs) include increased egg production and laying, increased rejection behavior (avoiding further male advances), decreased longevity, altered gustation and decrease...

journal_title：Journal of biological rhythms

authors： Garbe DS,Vigderman AS,Moscato E,Dove AE,Vecsey CG,Kayser MS,Sehgal A

更新日期：2016-12-01 00:00:00

abstract：:Intertidal species have both circadian and circatidal clocks. Although the behavioral evidence for these oscillators is more than 5 decades old, virtually nothing is known about their molecular clockwork. Pigment-dispersing hormones (PDHs) were originally described in crustaceans. Their insect homologs, pigment-disper...

journal_title：Journal of biological rhythms

authors： Beckwith EJ,Lelito KR,Hsu YW,Medina BM,Shafer O,Ceriani MF,de la Iglesia HO

更新日期：2011-12-01 00:00:00

abstract：:The possibility that feeding may act as a zeitgeber has been investigated in captive Svalbard ptarmigan by recording feeding or food-searching activity (FA) in birds given periodic access to food (PAF) under light-dark (LD) cycles or in continuous bright (LL) or dim light (DD) conditions. Except during LL, anticipator...

journal_title：Journal of biological rhythms

authors： Reierth E,Stokkan KA

更新日期：1998-10-01 00:00:00

abstract：:The annual cycle of reproductive function in starlings (Sturnus vulgaris) is driven by seasonal changes in daylength and consists of a 6-month period of photosensitivity, culminating in maximal gonadal development, followed by a 6-month period of photorefractoriness. If male starlings are held under a constant photope...

journal_title：Journal of biological rhythms

authors： Dawson A,McNaughton FJ

更新日期：1993-07-01 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：: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：: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：:During the first 7 weeks of postnatal life, short day lengths inhibit the onset of puberty in many photoperiodic rodents, but not in Syrian hamsters. In this species, timing of puberty and fecundity are independent of the early postnatal photoperiod. Gestational day length affects postnatal reproductive development in...

journal_title：Journal of biological rhythms

authors： Beery AK,Paul MJ,Routman DM,Zucker I

更新日期：2008-10-01 00:00:00

abstract：:Although overt diurnal rhythms of behavior do not begin until well after birth, molecular studies suggest that the circadian clock may begin much earlier at a cellular level: mouse embryonic fibroblasts, for example, already possess robust clocks. By multiple criteria, we found no circadian clock present in mouse embr...

journal_title：Journal of biological rhythms

authors： Kowalska E,Moriggi E,Bauer C,Dibner C,Brown SA

更新日期：2010-12-01 00:00:00

abstract：:From the mathematical study of simple models for circadian rhythm, the authors identified a clear effect of saturation in the enzyme kinetics on the promotion or suppression of a sustained oscillation. In the models, a clock gene (per gene) is transcribed to produce mRNAs, which are translated to produce proteins in t...

journal_title：Journal of biological rhythms

authors： Kurosawa G,Iwasa Y

更新日期：2002-12-01 00:00:00

abstract：:In Drosophila melanogaster, disruption of night by even short light exposures results in degradation of the clock protein TIMELESS (TIM), leading to shifts in the fly molecular and behavioral rhythms. Several lines of evidence indicate that light entrainment of the brain clock involves the blue-light photoreceptor cry...

journal_title：Journal of biological rhythms

authors： Ivanchenko M,Stanewsky R,Giebultowicz JM

更新日期：2001-06-01 00:00:00

abstract：:The circadian system in higher organisms temporally orchestrates rhythmic changes in a vast number of genes and gene products in different organs. Complex interactions between these components, both within and among cells, ultimately lead to rhythmic behavior and physiology. Identifying the plethora of circadian targe...

journal_title：Journal of biological rhythms

authors： De Haro L,Panda S

更新日期：2006-12-01 00:00:00

abstract：:The daily biological clock regulates the timing of sleep and physiological processes that are of fundamental importance to human health, performance, and well-being. Environmental parameters of relevance to biological clocks include (1) daily fluctuations in light intensity and temperature, and (2) seasonal changes in...

journal_title：Journal of biological rhythms

authors： Ciarleglio CM,Ryckman KK,Servick SV,Hida A,Robbins S,Wells N,Hicks J,Larson SA,Wiedermann JP,Carver K,Hamilton N,Kidd KK,Kidd JR,Smith JR,Friedlaender J,McMahon DG,Williams SM,Summar ML,Johnson CH

更新日期：2008-08-01 00:00:00

abstract：:While the rapid development of personal computers and high-throughput recording systems for circadian rhythms allow chronobiologists to produce huge amounts of data, the software to analyze them often lags behind. Here, we announce newly developed chronobiology software that is easy to use, compatible with many differ...

journal_title：Journal of biological rhythms

authors： Schmid B,Helfrich-Förster C,Yoshii T

更新日期：2011-10-01 00:00:00

abstract：:The circadian pacemaker of the SCN is a heterogeneous structure containing many single-cell oscillators that display phase differences in gene expression and electrical activity rhythms. Thus far, it is unknown how single neurons contribute to the population signal measured from the SCN. The authors used single-unit e...

journal_title：Journal of biological rhythms

authors： Rohling J,Wolters L,Meijer JH

更新日期：2006-08-01 00:00:00

abstract：:To determine if a circadian rhythm known to be functionally related to the reproductive axis varies on a circannual basis, we monitored the circadian secretion of melatonin at monthly intervals for 2 years in four ovariectomized, estradiol-implanted ewes held in a constant short-day photoperiod. Prior to the study, ew...

journal_title：Journal of biological rhythms

authors： Thrun LA,Moenter SM,O'Callaghan D,Woodfill CJ,Karsch FJ

更新日期：1995-03-01 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：:Entrainability of the circadian rhythm of mosquito flight and locomotor activity was investigated by giving a 24-hr temperature cycle (28 degrees C for 16 hr, 23 degrees C for 8 hr) to the free-running rhythm or by shifting the temperature cycle. The phase angle difference between the entrained rhythm and the temperat...

journal_title：Journal of biological rhythms

authors： Chiba Y,Uki M,Kawasaki Y,Matsumoto A,Tomioka K

更新日期：1993-10-01 00:00:00

abstract：:The authors analyzed the upstream regulatory region of purF, a gene that is expressed in a minority phase that peaks at dawn (class 2 circadian phasing) in Synechococcus elongatus, to determine whether specific cis elements are responsible for this characteristic expression pattern. Fusions of various promoter-bearing...

journal_title：Journal of biological rhythms

authors： Min H,Liu Y,Johnson CH,Golden SS

更新日期：2004-04-01 00:00:00

abstract：:Sex differences in circadian rhythms have been reported with some conflicting results. The timing of sleep and length of time in bed have not been considered, however, in previous such studies. The current study has 3 major aims: (1) replicate previous studies in a large sample of young adults for sex differences in s...

journal_title：Journal of biological rhythms

authors： Van Reen E,Sharkey KM,Roane BM,Barker D,Seifer R,Raffray T,Bond TL,Carskadon MA

更新日期：2013-12-01 00:00:00

abstract：:Activity patterns are the product of interactions between an internal circadian clock and direct responses to photic and nonphotic features of the environment that are said to "mask" the influence of that clock. Evolutionary transitions between nocturnality and diurnality involve changes in mechanisms underlying both ...

journal_title：Journal of biological rhythms

authors： Cohen R,Smale L,Kronfeld-Schor N

更新日期：2010-02-01 00:00:00

abstract：:We examine theoretical models for circadian oscillations based on transcriptional regulation in Drosophila and Neurospora. For Drosophila, the molecular model is based on the negative feedback exerted on the expression of the per and tim genes by the complex formed between the PER and TIM proteins. For Neurospora, sim...

journal_title：Journal of biological rhythms

authors： Leloup JC,Gonze D,Goldbeter A

更新日期：1999-12-01 00:00:00

abstract：:Siberian hamsters are photoperiodic seasonally breeding rodents. To date, there has been no evidence that Siberian hamsters exhibit an annual rhythm in reproductive, thermoregulatory, molt, or body mass changes. However, given that the termination of their winter cycle is under endogenous control, the authors thought ...

journal_title：Journal of biological rhythms

authors： Anchordoquy HC,Lynch GR

更新日期：2000-04-01 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：:The circadian clock represents an anticipatory mechanism, well preserved in evolution. It has a critical impact on most aspects of the physiology of light-sensitive organisms. These rhythmic processes are governed by environmental cues (fluctuations in light intensity and temperature), an internal circadian timing sys...

journal_title：Journal of biological rhythms

authors： Philippe J,Dibner C

更新日期：2015-04-01 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