This book sheds new light on the molecular mechanisms that generate circadian rhythms. It examines how biological rhythms influence physiological processes such as sleep, hormone synthesis and secretion, immunity, kidney function, the cardiovascular system, blood pressure, and the digestive system. Clinical implications are considered while exploring the impact of rhythms on neuropsychiatric disorders and chronotherapy’s potential for reducing cardiovascular risk. Offering a cross-section of expertise in both basic and translational (bench-to-bedside) research, this book serves as a guide for physicians and scientists who wish to learn more about the impact of circadian rhythms on physiological processes in health and disease.
In this book, leading experts in the field review how circadian rhythms impact the brain. An essential function of mammalian life is the exploitation of the regularities provided by the 24-hour cycle of day and night. The development and evolution of circadian clock mechanisms have allowed us to optimally adapt our behavior and physiology to the external world. Not surprisingly, a growing body of evidence links the disruption of circadian rhythms by genetic, lifestyle and environmental factors to illnesses of the brain. In the first section of the book, readers will learn about the molecular and anatomic architecture of circadian function in mammals. The ways in which environmental disruptions and misalignments can influence such mechanisms and therefore impair brain function and health status are also addressed. In the second part, the focus shifts to those brain regions responsible for brain function and the body-wide regulation of circadian function. Amongst others, special attention is paid to the role of astrocytes and the brain’s reward and hyprocretin / orexin systems. The book concludes with an extensive discussion on the consequences of circadian rhythm dysfunction. Several chapters present the latest findings on Attention Deficit Hyperactivity Disorder, schizophrenia, autism spectrum disorder, drug abuse and mood disorders. Written by auhorities in the field, the book provides a state-of-the-art review of the latest findings on circadian clocks in the brain and highlights their potentially far-reaching impacts on our health and well-being. As such, it is essential reading for all neuroscientists and clinicians seeking to understand the intricate connections between circadian rhythms and brain health and illness.
With the invitation to edit this volume, I wanted to take the opportunity to assemble reviews on different aspects of circadian clocks and rhythms. Although most c- tributions in this volume focus on mammalian circadian clocks, the historical int- duction and comparative clocks section illustrate the importance of various other organisms in deciphering the mechanisms and principles of circadian biology. Circadian rhythms have been studied for centuries, but only recently, a mole- lar understanding of this process has emerged. This has taken research on circadian clocks from mystic phenomenology to a mechanistic level; chains of molecular events can describe phenomena with remarkable accuracy. Nevertheless, current models of the functioning of circadian clocks are still rudimentary. This is not due to the faultiness of discovered mechanisms, but due to the lack of undiscovered processes involved in contributing to circadian rhythmicity. We know for example, that the general circadian mechanism is not regulated equally in all tissues of m- mals. Hence, a lot still needs to be discovered to get a full understanding of cir- dian rhythms at the systems level. In this respect, technology has advanced at high speed in the last years and provided us with data illustrating the sheer complexity of regulation of physiological processes in organisms. To handle this information, computer aided integration of the results is of utmost importance in order to d- cover novel concepts that ultimately need to be tested experimentally.
Circadian rhythms, the biological oscillations based around our 24-hour clock, have a profound effect on human physiology and healthy cellular function. Circadian Rhythms: Health and Disease is a wide-ranging foundational text that provides students and researchers with valuable information on the molecular and genetic underpinnings of circadian rhythms and looks at the impacts of disruption in our biological clocks in health and disease. Circadian Rhythms opens with chapters that lay the fundamental groundwork on circadian rhythm biology. Section II looks at the impact of circadian rhythms on major organ systems. Section III then turns its focus to the central nervous system. The book then closes with a look at the role of biological rhythms in aging and neurodegeneration. Written in an accessible and informative style, Circadian Rhythms: Health and Disease,will be an invaluable resource and entry point into this fascinating interdisciplinary field that brings together aspects of neuroscience, cell and molecular biology, and physiology.
This latest volume in Advances in Genetics covers the genetics of Circadian rhythms. With an international group of authors this volume is the latest offering in this widely praised series.
One of the major breakthroughs of the last decade in the understanding of energy homeostasis is the identification of a reciprocal control between circadian rhythmicity and cellular metabolism. Circadian rhythmicity is a fundamental endogenous process of almost every organism living on Earth. For instance, the alternation of hunger and satiety is not continuous over 24 h, but is instead structured in time along the light/dark cycle. In mammals, the temporal organization of metabolism, physiology and behavior around 24 h is controlled by a network of multiple cellular clocks, synchronized via neuronal and hormonal signals by a master clock located in the suprachiasmatic nuclei of the hypothalamus. This central circadian conductor in the brain is mainly reset by ambient light perceived by the retina, while secondary circadian clocks in other brain areas and peripheral organs can be reset by meal timing. Chronic disruption of circadian rhythms, as seen in human shift-workers (up to 20% of the active population), has been associated with the development of a number of adverse mental and metabolic conditions. Understanding of the functional links between circadian desynchronization and overall health in animal models and humans, however, is still scarce. Interactions between circadian clocks and metabolism can occur at different levels: the molecular clockwork, internal synchronization via neuro-hormonal signals, or external synchronization via photic or feeding cues. This Research Topic comprises a number of reviews as well as research and methods articles that feature recent advancements in the mechanisms linking circadian clocks with energy metabolism, and the pathophysiological implications of these interactions for metabolic health.
The nature of the circadian clocks is described at the molecular, cellular, tissue, and system levels of organization in diverse organisms. The central role of the circadian clock in the regulation of the sleep-wake cycle as well as seasonal rhythms and other cyclical processes is also discussed. The importance of the circadian clock system for human health, safety, performance, and productivity is also reviewed in this volume."--BOOK JACKET.
This book summarizes the recent advances for the understanding of circadian clock system in the regulation of drug metabolism and pharmacokinetics. Basic knowledge in the field of circadian clock and pharmacokinetics are systemically introduced to make it easier for readers to understand the entire book's contents. The rhythmic expression of DMEs (drug-metabolizing enzymes) and transporters are summarized, and the underlying mechanisms thereof (i.e., regulation by circadian oscillators) are discussed. Typically, evidence for the DME- and transporter-mediated chronopharmacokinetics, chronotoxicity and chronoefficacy are highlighted in this book.
Circadian rhythms are biological processes displaying endogenous and entrainable oscillations of about 24 hours. They are driven by a group of genes called clock genes that have been widely observed in plants, animals and even in bacteria. In mammals, the core clock genes are rhythmically expressed in both the suprachiasmatic nucleus (SCN), the master clock residing in the hypothalamus, and almost all peripheral tissues where they control numerous target genes in a circadian manner, and thus affect many physiological and biochemical processes. Evidence suggests that disruption of the circadian rhythms (or desynchronization) is a significant risk factor for the development of metabolic diseases, cardiovascular diseases, cancer and sleep disorders. Evidence also suggests that the disruption suppresses immune function and increases vulnerability to infectious diseases. Restoring or strengthening the circadian rhythm may be therapeutic for these conditions. This becomes exceptionally important in modern societies because many people are suffering from frequent desynchronization due to shift working, exposure to artificial light, travel by transmeridian air flight, and involvement in social activities. Besides, the temporal variations in the incidence and severity of many diseases, such as the onset of cardiovascular events, chronic obstructive pulmonary disease (COPD), inflammatory diseases and mental disorders have also drawn increasing attention to the circadian clock. The circadian rhythms affect not only the health status, but also the drug efficiency. The effects (and side effects) of many drugs vary with biological timing. The tolerance of many medications displays circadian variation as well. The timing of medical treatment in coordination with the body clock may significantly increase the desired effects of drugs, and lower the dose and toxicity. In addition, circadian rhythms can also be modulated by some therapeutic drugs, for example, melatonin and modafinil, which are used to treat circadian rhythm sleep disorders. In this Research Topic, we assemble a series of critical review and research articles that focus on the therapeutic implications of circadian rhythms. Topics include, but are not limited to: • Circadian disruption caused diseases or disorders and related intervention • Temporal manifestation of diseases or disorders and therapeutic implications • The effects of circadian rhythms on drugs • The effects of drugs on circadian rhythms
