Coordination of circadian timing in mammals

@article{Reppert2002CoordinationOC,
  title={Coordination of circadian timing in mammals},
  author={Steven M. Reppert and David R. Weaver},
  journal={Nature},
  year={2002},
  volume={418},
  pages={935-941}
}
Time in the biological sense is measured by cycles that range from milliseconds to years. Circadian rhythms, which measure time on a scale of 24 h, are generated by one of the most ubiquitous and well-studied timing systems. At the core of this timing mechanism is an intricate molecular mechanism that ticks away in many different tissues throughout the body. However, these independent rhythms are tamed by a master clock in the brain, which coordinates tissue-specific rhythms according to light… Expand

Figures and Topics from this paper

The genetic basis of circadian behavior
  • H. Oster
  • Biology, Medicine
  • Genes, brain, and behavior
  • 2006
TLDR
In most species, an endogenous timing system synchronizes physiology and behavior to the rhythmic succession of day and night through a set of interwoven transcriptional/translational feedback loops. Expand
The mammalian circadian clock.
TLDR
Genetic, biochemical and genomic approaches have led to major advances in understanding the molecular and cellular basis of mammalian circadian clock components and mechanisms. Expand
Circadian rhythms in stem cell biology and function
The mammalian circadian clock is a time-keeping system that adapts the body physiology to light/dark cycles with a period of 24 hours. It consists of a central clock in the suprachiasmatic nucleusExpand
Minutes, days and years: molecular interactions among different scales of biological timing
TLDR
This review summarizes current findings on the neurobiological basis of the circadian system, both at the genetic and behavioural level, and also focuses on its interactions with interval timing and seasonal rhythms, in order to construct a multi-level biological clock. Expand
Avian Circadian Organization
This chapter details the organization of the avian circadian clock systems starting with the systemic levels of circadian organization that perceives the external cue (light) and then generates theExpand
The clock shop: Coupled circadian oscillators
TLDR
A review of recent studies highlights the roles of specific intracellular and intercellular signals within the SCN that underlie circadian synchrony. Expand
Neurobiology of Circadian Systems
TLDR
The fact that non-pharmacological and pharmacological therapies of affective disorders influence circadian rhythms indicates that biological clocks play a role in the pathophysiology of these disorders. Expand
Circadian Rhythms in Health and Disease
TLDR
Intrinsic body clocks evolved in almost all organisms, ranging from fungi, bacteria, plants, to animals including humans, to time the organism’s behavior and physiology in accordance with their environmental 24-h day, which enhances the chances of survival. Expand
Orchestration of gene expression and physiology by the circadian clock
  • U. Albrecht
  • Biology, Medicine
  • Journal of Physiology-Paris
  • 2006
TLDR
In this review, the principle of the clock mechanism, its synchronization to the environment and consequences on health when the circadian clock is disrupted are described. Expand
A Web of Circadian Pacemakers
The mammalian circadian timing system is composed of almost as many individual clocks as there are cells. These countless oscillators have to be synchronized by a central pacemaker to coordinateExpand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 91 REFERENCES
Molecular analysis of mammalian circadian rhythms.
TLDR
Greater understanding of the cellular and molecular mechanisms of the SCN clockwork provides opportunities for pharmacological manipulation of circadian timing. Expand
Entrainment of the circadian clock in the liver by feeding.
TLDR
It is demonstrated that feeding cycles can entrain the liver independently of the SCN and the light cycle, and the need to reexamine the mammalian circadian hierarchy is suggested, raising the possibility that peripheral circadian oscillators like those in the liver may be coupled to theSCN primarily through rhythmic behavior, such as feeding. Expand
Coordinated Transcription of Key Pathways in the Mouse by the Circadian Clock
TLDR
Genetic and genomic analysis suggests that a relatively small number of output genes are directly regulated by core oscillator components, and major processes regulated by the SCN and liver were found to be under circadian regulation. Expand
Mammalian Cry1 and Cry2 are essential for maintenance of circadian rhythms
TLDR
It is shown that mice lacking the Cry1 or Cry2 protein display accelerated and delayed free-running periodicity of locomotor activity, respectively, which suggests that, in addition to a possible photoreceptor and antagonistic clock-adjusting function, both proteins are essential for the maintenance of circadian rhythmicity. Expand
Resetting central and peripheral circadian oscillators in transgenic rats.
TLDR
It is hypothesize that a self-sustained circadian pacemaker in the SCN entrains circadian oscillators in the periphery to maintain adaptive phase control, which is temporarily lost following large, abrupt shifts in the environmental light cycle. Expand
Morning and evening circadian oscillations in the suprachiasmatic nucleus in vitro
TLDR
It is demonstrated that the circadian rhythm of SCN electrophysiological activity, recorded as a single daytime peak in hamster hypothalamic coronal slices, shows two distinct peaks when slices are cut in the horizontal plane, which indicate functional organization ofSCN tissue as a clock with two oscillating components. Expand
Time zones: a comparative genetics of circadian clocks
TLDR
The circadian clock is a widespread cellular mechanism that underlies diverse rhythmic functions in organisms from bacteria and fungi, to plants and animals, and the weight of evidence favours their independent evolutionary origins in different kingdoms. Expand
Diurnal modulation of pacemaker potentials and calcium current in the mammalian circadian clock
TLDR
Day–night modulation of Ca2+ current is a central step in transducing the intracellular cycling of molecular clocks to the rhythm in spontaneous firing rate. Expand
Resetting of circadian time in peripheral tissues by glucocorticoid signaling.
TLDR
It is shown that the glucocorticoid hormone analog dexamethasone induces circadian gene expression in cultured rat-1 fibroblasts and transiently changes the phase of circadian gene Expression in liver, kidney, and heart, however, dexamETHasone does not affect cyclic geneexpression in neurons of the suprachiasmatic nucleus. Expand
Interacting molecular loops in the mammalian circadian clock.
TLDR
Analysis of Clock/Clock mutant mice, homozygous Period2(Brdm1) mutants, and Cryptochrome-deficient mice reveals substantially altered Bmal1 rhythms, consistent with a dominant role of PERIOD2 in the positive regulation of the Bmal 1 loop. Expand
...
1
2
3
4
5
...