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 embryonic stem cells. Nevertheless, upon their differentiation into neurons, circadian gene expression was observed. In the first steps along the pathway from ES cells to neurons, a neural precursor cell (NPC) line already showed robust circadian oscillations. Therefore, at a cellular level, the circadian clock likely begins at the very earliest stages of mammalian development.
journal_name
J Biol Rhythmsjournal_title
Journal of biological rhythmsauthors
Kowalska E,Moriggi E,Bauer C,Dibner C,Brown SAdoi
10.1177/0748730410385281subject
Has Abstractpub_date
2010-12-01 00:00:00pages
442-9issue
6eissn
0748-7304issn
1552-4531pii
25/6/442journal_volume
25pub_type
杂志文章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
pub_type： 杂志文章
doi：10.1177/0748730406290317
更新日期：2006-08-01 00:00:00
abstract：:The retinohypothalamic tract (RHT), a monosynaptic retinal projection to the SCN, is the major path by which light entrains the circadian system to the external photoperiod. The circadian system of rodents effectively integrates or counts photons, and the magnitude of the rhythm phase response is proportional to the t...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730405280458
更新日期：2005-12-01 00:00:00
abstract：:The classical power spectrum, computed in the frequency domain, outranks traditionally used periodograms derived in the time domain (such as the chi2 periodogram) regarding the search for biological rhythms. Unfortunately, classical power spectral analysis is not possible with unequally spaced data (e.g., time series ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873099129000984
更新日期：1999-12-01 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
pub_type： 杂志文章
doi：10.1177/074873002129002645
更新日期：2002-08-01 00:00:00
abstract：:Threads of evidence from recent experimentation in retinal morphology, neurochemistry, electrophysiology, and visual perception point toward rhythmic ocular processes that may be integral components of circadian entrainment in mammals. Components of retinal cell biology (rod outer-segment disk shedding, inner-segment ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章,评审
doi：10.1177/074873049100600104
更新日期：1991-04-01 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
pub_type： 杂志文章
doi：10.1177/074873049601100205
更新日期：1996-06-01 00:00:00
abstract：:A 12-hr dark period, at a temperature high enough to permit time measurement to occur, is necessary for maximal induction of larval diapause in the European corn borer, Ostrinia nubilalis. In the present study, induction of diapause only occurred in a periodic environment. This was in the form of certain (1) light-dar...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873048600100205
更新日期：1986-07-01 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
pub_type： 信件
doi：10.1177/0748730411414264
更新日期：2011-10-01 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
pub_type： 杂志文章
doi：10.1177/0748730408320284
更新日期：2008-08-01 00:00:00
abstract：:Systematic treatment of hamsters with triazolam (TRZ) or novel wheel (NW) access will yield PRCs similar to those for neuropeptide Y. Both TRZ and NW access require an intact intergeniculate leaflet (IGL) to modulate circadian rhythm phase. It is commonly suggested that both stimulus types influence rhythm phase respo...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873098129000327
更新日期：1998-12-01 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
pub_type： 杂志文章
doi：10.1177/074873049601100104
更新日期：1996-03-01 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
pub_type： 杂志文章,评审
doi：10.1177/0748730405277388
更新日期：2005-08-01 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
pub_type： 信件
doi：10.1177/0748730416654024
更新日期：2016-08-01 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
pub_type： 杂志文章
doi：10.1177/074873099129000713
更新日期：1999-08-01 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
pub_type： 杂志文章
doi：10.1177/0748730412440851
更新日期：2012-06-01 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
pub_type： 杂志文章
doi：10.1177/0748730402238239
更新日期：2002-12-01 00:00:00
abstract：:African sleeping sickness is characterized by alterations in rhythmic functions. It is not known if the disease affects the expression of clock genes, which are the molecular basis for rhythm generation. We used a chronic rat model of experimental sleeping sickness, caused by the extracellular parasite Trypanosoma bru...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730409360963
更新日期：2010-04-01 00:00:00
abstract：:The large repertoire of circadian rhythms in diverse organisms depends on oscillating central clock genes, input pathways for entrainment, and output pathways for controlling rhythmic behaviors. Stress-activated p38 MAP Kinases (p38K), although sparsely investigated in this context, show circadian rhythmicity in mamma...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730414555183
更新日期：2014-12-01 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
pub_type： 杂志文章
doi：10.1177/0748730410396678
更新日期：2011-04-01 00:00:00
abstract：:The adjustment of hamsters to advanced light-dark (LD) cycles can be greatly accelerated by scheduling a single 3-hr bout of extra activity in a novel running wheel, starting about 7 hr before the time when the animals become active in the preceding LD cycle. The present experiments were designed to provide stronger e...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873048900400305
更新日期：1989-10-01 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
pub_type： 杂志文章
doi：10.1177/0748730410368244
更新日期：2010-06-01 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
pub_type： 杂志文章
doi：10.1177/074873049300800204
更新日期：1993-07-01 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
pub_type： 杂志文章
doi：10.1177/0748730409351672
更新日期：2010-02-01 00:00:00
abstract：:Siberian hamsters (Phodopus sungorus) exhibit changes in immune function following adaptation to short photoperiods, including a marked attenuation of energetically expensive thermoregulatory and behavioral responses to gram-negative bacterial infections. Whether this seasonal attenuation of the immune response is idi...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730407311518
更新日期：2008-02-01 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
pub_type： 杂志文章
doi：10.1177/074873049501000104
更新日期：1995-03-01 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
pub_type： 杂志文章
doi：10.1177/0748730414537801
更新日期：2014-06-01 00:00:00
abstract：:Rhodopsin 7 ( Rh7), a new invertebrate Rhodopsin gene, was discovered in the genome of Drosophila melanogaster in 2000, but its function has remained elusive. We generated an Rh7 null mutant ( Rh70) by P element-mediated mutagenesis and found that an absence of Rh7 had significant effects on fly activity patterns duri...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730417721826
更新日期：2017-10-01 00:00:00
abstract：:Nonphotic stimuli can reset and entrain circadian activity rhythms in hamsters and mice, and serotonin is thought to be involved in the phase-resetting effects of these stimuli. In the present study, the authors examined the effect of the serotonin agonist quipazine on circadian activity rhythms in three inbred strain...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873099129000524
更新日期：1999-04-01 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
pub_type： 杂志文章
doi：10.1177/074873049000500106
更新日期：1990-04-01 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
pub_type： 杂志文章
doi：10.1177/074873040101600303
更新日期：2001-06-01 00:00:00
