Abstract:
:Ground squirrels, Spermophilus tridecemlineatus, were kept in a 12:12 h light-dark cycle. As expected for a diurnal species, their locomotor activity occurred almost entirely in the daytime. Expression of mPer1 and mPer2 in the suprachiasmatic nucleus was studied at six time points by in situ hybridization. For both these genes, mRNA was highest in the first part of the subjective day (about zeitgeber time 5). This is close to the time when mPer1 and mPer2 expression is maximal in nocturnal rodents. These results have implications for understanding nonphotic phase response curves in diurnal species and thereby for guiding research on nonphotic phase shifting in people.
journal_name
J Biol Rhythmsjournal_title
Journal of biological rhythmsauthors
Mrosovsky N,Edelstein K,Hastings MH,Maywood ESdoi
10.1177/074873001129002141subject
Has Abstractpub_date
2001-10-01 00:00:00pages
471-8issue
5eissn
0748-7304issn
1552-4531journal_volume
16pub_type
杂志文章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
pub_type: 杂志文章
doi:10.1177/0748730417738612
更新日期:2018-02-01 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
pub_type: 杂志文章
doi:10.1177/074873048800300103
更新日期:1988-04-01 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::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
pub_type: 杂志文章
doi:10.1177/0748730420965291
更新日期:2020-12-01 00:00:00
abstract::An intricate transcription-translation feedback loop (TTFL) governs cellular circadian rhythms in mammals. Here, we report that the zinc finger transcription factor Krüppel-like factor 9 (KLF9) is regulated by this TTFL, it associates in chromatin at the core circadian clock and clock-output genes, and it acts to modu...
journal_title:Journal of biological rhythms
pub_type: 杂志文章
doi:10.1177/0748730420913205
更新日期:2020-06-01 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::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
pub_type: 杂志文章,评审
doi:10.1177/0748730409344800
更新日期:2009-10-01 00:00:00
abstract::Honey bee workers care for ("nurse") the brood around the clock without circadian rhythmicity, but then they forage outside with strong circadian rhythms and a consolidated nightly rest. This chronobiological plasticity is associated with variation in the expression of the canonical "clock genes" that regulate the cir...
journal_title:Journal of biological rhythms
pub_type: 杂志文章
doi:10.1177/0748730411431404
更新日期:2012-02-01 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::The circadian clock plays an important role in adaptation in time and space by synchronizing changes in physiological, developmental, and behavioral traits of organisms with daily and seasonal changes in their environment. We have studied some features of the circadian activity and clock organization in a northern Dro...
journal_title:Journal of biological rhythms
pub_type: 杂志文章
doi:10.1177/0748730412455916
更新日期:2012-10-01 00:00:00
abstract::Abstract The cyanobacterial clock protein KaiC regulates the circadian cycle by exhibiting rhythms in transcription, translation, and phosphorylation. KaiC phosphorylation persists in circadian cycling even under transcription-less conditions and was reconstituted in vitro by incubating KaiC, KaiA, and KaiB. This pres...
journal_title:Journal of biological rhythms
pub_type: 杂志文章
doi:10.1177/0748730406291329
更新日期:2006-10-01 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::There is little evidence for the involvement of microRNAs (miRs) in the regulation of circadian rhythms, despite the potential relevance of these elements in the posttranscriptional regulation of the clock machinery. The present work aimed to identify miRs targeting circadian genes through a predictive analysis of con...
journal_title:Journal of biological rhythms
pub_type: 杂志文章
doi:10.1177/0748730413476827
更新日期:2013-04-01 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
pub_type: 杂志文章
doi:10.1177/0748730410385281
更新日期:2010-12-01 00:00:00
abstract::Whether the circatidal rhythm is generated by a machinery common to the circadian clock is one of the important and interesting questions in chronobiology. The mangrove cricket Apteronemobius asahinai shows a circatidal rhythm generating active and inactive phases and a circadian rhythm modifying the circatidal rhythm...
journal_title:Journal of biological rhythms
pub_type: 杂志文章
doi:10.1177/0748730413516309
更新日期:2014-02-01 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
pub_type: 杂志文章,评审
doi:10.1177/0748730403254971
更新日期:2003-08-01 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
pub_type: 杂志文章
doi:10.1177/0748730406287996
更新日期:2006-06-01 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
pub_type: 杂志文章,评审
doi:10.1177/0748730403018003005
更新日期:2003-06-01 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
pub_type: 杂志文章
doi:10.1177/074873048700200104
更新日期:1987-04-01 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::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
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abstract::The hematologic system performs a number of essential functions, including oxygen transport, the execution of the immune response against tumor cells and invading pathogens, and hemostasis (blood clotting). These roles are performed by erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (p...
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更新日期:2015-10-01 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
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更新日期:1989-04-01 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::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
pub_type: 杂志文章
doi:10.1177/0748730406294767
更新日期:2006-12-01 00:00:00
abstract::The synchronizing stimulus, its transduction site, and the afferent pathways responsible for feeding entrainment remain unknown. In fish, the role of the diet in the development of feeding anticipatory activity (FAA) is not well understood and fundamental questions on the mechanisms of feeding entrainment, such as the...
journal_title:Journal of biological rhythms
pub_type: 杂志文章
doi:10.1177/074873040101600107
更新日期:2001-02-01 00:00:00
abstract::The mammalian circadian pacemaker is located in the suprachiasmatic nucleus (SCN). Various inputs modulate pacemaker phase, including the serotonergic (5HTergic) input from the midbrain raphe. 5HT phase-advances the SCN pacemaker when applied during mid subjective day. In vitro studies indicate that 5HT advances the m...
journal_title:Journal of biological rhythms
pub_type: 杂志文章
doi:10.1177/074873002129002429
更新日期:2002-04-01 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
pub_type: 杂志文章
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更新日期:2019-08-01 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...
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pub_type: 杂志文章
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更新日期:2008-12-01 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...
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更新日期:1993-07-01 00:00:00