The Mammalian Circadian Timing System: Organization and Coordination of Central and Peripheral Clocks

Annual Review of Physiology, Год журнала: 2010, Номер 72(1), С. 517 - 549

Опубликована: Фев. 11, 2010

Most physiology and behavior of mammalian organisms follow daily oscillations. These rhythmic processes are governed by environmental cues (e.g., fluctuations in light intensity temperature), an internal circadian timing system, the interaction between this timekeeping system signals. In mammals, has a complex architecture, composed central pacemaker brain's suprachiasmatic nuclei (SCN) subsidiary clocks nearly every body cell. The clock is synchronized to geophysical time mainly via photic perceived retina transmitted electrical signals SCN neurons. turn, influences neuronal humoral synchronization local oscillators that operative cells most organs tissues. Thus, some output pathways serve as input for peripheral Here we discuss knowledge acquired during past few years on structure function system.

Язык: Английский

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Suprachiasmatic Nucleus: Cell Autonomy and Network Properties

Annual Review of Physiology, Год журнала: 2010, Номер 72(1), С. 551 - 577

Опубликована: Фев. 11, 2010

The suprachiasmatic nucleus (SCN) is the primary circadian pacemaker in mammals. Individual SCN neurons dispersed culture can generate independent oscillations of clock gene expression and neuronal firing. However, rhythmicity depends on sufficient membrane depolarization levels intracellular calcium cAMP. In intact SCN, cellular are synchronized reinforced by rhythmic synaptic input from other cells, resulting a reproducible topographic pattern distinct phases amplitudes specified circuit organization. network synchronizes its component oscillators, reinforces their oscillations, responds to light altering phase distribution, increases robustness genetic perturbations, enhances precision. Thus, even though individual be cell-autonomous properties integral normal function SCN.

Язык: Английский

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Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery

Pharmacological Reviews, Год журнала: 2009, Номер 61(3), С. 283 - 357

Опубликована: Сен. 1, 2009

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a 38-amino acid C-terminally α-amidated peptide that was first isolated 20 years ago from an ovine hypothalamic extract on the basis of its ability to stimulate cAMP formation in anterior pituitary cells (Miyata et al., 1989. PACAP belongs vasoactive intestinal (VIP)-secretin-growth hormone-releasing hormone-glucagon superfamily. The sequence has been remarkably well conserved during evolution protochordates mammals, suggesting involved regulation important biological functions. widely distributed brain and peripheral organs, notably endocrine pancreas, gonads, respiratory urogenital tracts. Characterization precursor revealed existence PACAP-related peptide, activity which remains unknown. Two types binding sites have characterized: type I exhibit high affinity for much lower VIP, whereas II similar VIP. Molecular cloning receptors shown three distinct receptor subtypes: PACAP-specific PAC1-R, coupled several transduction systems, PACAP/VIP-indifferent VPAC1-R VPAC2-R, are primarily adenylyl cyclase. PAC1-Rs particularly abundant brain, adrenal gland, VPAC expressed mainly lung, liver, testis. development transgenic animal models specific ligands strongly contributed deciphering various actions PACAP. Consistent with wide distribution receptors, now exert large array pharmacological effects present report reviews current knowledge concerning pleiotropic discusses possible use future therapeutic applications.

Язык: Английский

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Physiology of Circadian Entrainment

Physiological Reviews, Год журнала: 2010, Номер 90(3), С. 1063 - 1102

Опубликована: Июль 1, 2010

Mammalian circadian rhythms are controlled by endogenous biological oscillators, including a master clock located in the hypothalamic suprachiasmatic nuclei (SCN). Since period of this oscillation is ∼24 h, to keep synchrony with environment, need be entrained daily means Zeitgeber (“time giver”) signals, such as light-dark cycle. Recent advances neurophysiology and molecular biology rhythmicity allow better understanding synchronization. In review we cover several aspects mechanisms for photic entrainment mammalian rhythms, retinal sensitivity light novel photopigments well variations retina that contribute regulation physiology. Downstream from retina, examine retinohypothalamic communication through neurotransmitter (glutamate, aspartate, pituitary adenylate cyclase-activating polypeptide) interaction SCN receptors resulting signal transduction pathways neurons, putative neuron-glia interactions. Finally, describe analyze gene expression its importance mechanisms, disorders or diseases related deficits, experimental clinical treatments.

Язык: Английский

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Peroxiredoxins are conserved markers of circadian rhythms

Nature, Год журнала: 2012, Номер 485(7399), С. 459 - 464

Опубликована: Май 15, 2012

Язык: Английский

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Intercellular Coupling Confers Robustness against Mutations in the SCN Circadian Clock Network

Cell, Год журнала: 2007, Номер 129(3), С. 605 - 616

Опубликована: Май 1, 2007

Язык: Английский

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Circadian rhythm disturbances in depression

Human Psychopharmacology Clinical and Experimental, Год журнала: 2008, Номер 23(7), С. 571 - 585

Опубликована: Авг. 5, 2008

Abstract Objective The aim of this article is to review progress in understanding the mechanisms that underlie circadian and sleep rhythms, their role pathogenesis treatment depression. Methods Literature was selected principally by Medline searches, additional reports were identified based on ongoing research activities authors' laboratory. Results Many physiological processes show rhythms activity. Sleep waking are most obvious mammals. There considerable evidence disturbances important pathophysiology mood disorders. Depressed patients often altered disturbances, diurnal variation. Chronotherapies, including bright light exposure, deprivation, social rhythm therapies, may be useful adjuncts non‐seasonal seasonal Antidepressant drugs have marked effects sleep. Conclusions Recent chronobiological regulation provide novel insights avenues into development new pharmacological behavioral strategies for Copyright © 2008 John Wiley & Sons, Ltd.

Язык: Английский

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Genetics of Circadian Rhythms in Mammalian Model Organisms

Advances in genetics, Год журнала: 2011, Номер unknown, С. 175 - 230

Опубликована: Янв. 1, 2011

Язык: Английский

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Metabolism and Circadian Rhythms—Implications for Obesity

Endocrine Reviews, Год журнала: 2009, Номер 31(1), С. 1 - 24

Опубликована: Окт. 23, 2009

Obesity has become a serious public health problem and major risk factor for the development of illnesses, such as insulin resistance hypertension. Human homeostatic systems have adapted to daily changes in light dark way that body anticipates sleep activity periods. Mammals developed an endogenous circadian clock located suprachiasmatic nuclei anterior hypothalamus responds environmental light-dark cycle. Similar clocks been found peripheral tissues, liver, intestine, adipose tissue, regulating cellular physiological functions. The reported regulate metabolism energy homeostasis liver other tissues. This is achieved by mediating expression and/or certain metabolic enzymes transport systems. In return, key transcription activators interact with affect core mechanism. addition, mechanism shown be linked lipogenic adipogenic pathways. Animals mutations genes disrupt rhythmicity provided evidence relationship between homeostasis. clinical studies shift workers obese patients accentuate link metabolism. review will focus on interconnection metabolism, implications obesity how influenced hormones, nutrients, timed meals.

Язык: Английский

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Linking neural activity and molecular oscillations in the SCN

Nature reviews. Neuroscience, Год журнала: 2011, Номер 12(10), С. 553 - 569

Опубликована: Сен. 2, 2011

Язык: Английский

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