Curr Biol 2017 Sep 17;27(17):2623-2629.e2. Epub 2017 Aug 17.
Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden. Electronic address:
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Mol Brain 2009 Aug 27;2:28. Epub 2009 Aug 27.
Faculty of Life Sciences, University of Manchester, Manchester, UK.
Background: In mammals, the synchronized activity of cell autonomous clocks in the suprachiasmatic nuclei (SCN) enables this structure to function as the master circadian clock, coordinating daily rhythms in physiology and behavior. However, the dominance of this clock has been challenged by the observations that metabolic duress can over-ride SCN controlled rhythms, and that clock genes are expressed in many brain areas, including those implicated in the regulation of appetite and feeding. The recent development of mice in which clock gene/protein activity is reported by bioluminescent constructs (luciferase or luc) now enables us to track molecular oscillations in numerous tissues ex vivo. Read More
J Vis Exp 2012 Sep 27(67). Epub 2012 Sep 27.
Department of Biological Sciences, The University of Memphis, USA.
In mammals, many aspects of behavior and physiology such as sleep-wake cycles and liver metabolism are regulated by endogenous circadian clocks (reviewed). The circadian time-keeping system is a hierarchical multi-oscillator network, with the central clock located in the suprachiasmatic nucleus (SCN) synchronizing and coordinating extra-SCN and peripheral clocks elsewhere. Individual cells are the functional units for generation and maintenance of circadian rhythms, and these oscillators of different tissue types in the organism share a remarkably similar biochemical negative feedback mechanism. Read More
PLoS Biol 2008 Nov;6(11):e273
Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT, USA.
Drosophila clock neurons are self-sustaining cellular oscillators that rely on negative transcriptional feedback to keep circadian time. Proper regulation of organismal rhythms of physiology and behavior requires coordination of the oscillations of individual clock neurons within the circadian control network. Over the last decade, it has become clear that a key mechanism for intercellular communication in the circadian network is signaling between a subset of clock neurons that secrete the neuropeptide pigment dispersing factor (PDF) and clock neurons that possess its G protein-coupled receptor (PDFR). Read More
Endocrinol Metab (Seoul) 2015 Sep 9;30(3):361-70. Epub 2014 Dec 9.
Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, Seoul, Korea.
Background: In mammals, the master circadian pacemaker is localized in an area of the ventral hypothalamus known as the suprachiasmatic nucleus (SCN). Previous studies have shown that pacemaker neurons in the SCN are highly coupled to one another, and this coupling is crucial for intrinsic self-sustainability of the SCN central clock, which is distinguished from peripheral oscillators. One plausible mechanism underlying the intercellular communication may involve direct electrical connections mediated by gap junctions. Read More