Inhibitory Regulation Of Excitatory Neurotransmission

Darlison’s excellent work reviews aspects of GABA-A receptor function, as well as the properties of a variety of other important inhibitory proteins, such as GABA-C receptors and G-protein coupled receptors including neuropeptides. Glycine receptors and potassium channels are covered too. The consequences of mutations that disrupt the regulation of excitatory neurotransmission, and efforts to target the GABAergic system for therapeutic benefit, are also discussed.

Glutamate is the most pervasive neurotransmitter in the central nervous system (CNS). Despite this fact, no validated biological markers, or biomarkers, currently exist for measuring glutamate pathology in CNS disorders or injuries. Glutamate dysfunction has been associated with an extensive range of nervous system diseases and disorders. Problems with how the neurotransmitter glutamate functions in the brain have been linked to a wide variety of disorders, including schizophrenia, Alzheimer's, substance abuse, and traumatic brain injury. These conditions are widespread, affecting a large portion of the United States population, and remain difficult to treat. Efforts to understand, treat, and prevent glutamate-related disorders can be aided by the identification of valid biomarkers. The Institute of Medicine's Forum on Neuroscience and Nervous System Disorders held a workshop on June 21-22, 2010, to explore ways to accelerate the development, validation, and implementation of such biomarkers. Glutamate-Related Biomarkers in Drug Development for Disorders of the Nervous System: Workshop Summary investigates promising current and emerging technologies, and outlines strategies to procure resources and tools to advance drug development for associated nervous system disorders. Moreover, this report highlights presentations by expert panelists, and the open panel discussions that occurred during the workshop.

Jasper's Basic Mechanisms, Fourth Edition, is the newest most ambitious and now clinically relevant publishing project to build on the four-decade legacy of the Jasper's series. In keeping with the original goal of searching for "a better understanding of the epilepsies and rational methods of prevention and treatment.", the book represents an encyclopedic compendium neurobiological mechanisms of seizures, epileptogenesis, epilepsy genetics and comordid conditions. Of practical importance to the clinician, and new to this edition are disease mechanisms of genetic epilepsies and therapeutic approaches, ranging from novel antiepileptic drug targets to cell and gene therapies.

Fundamental biochemical studies of basic brain metabolism focusing on the neuroactive amino acids glutamate and GABA combined with the seminal observation that one of the key enzymes, glutamine synthetase is localized in astroglial cells but not in neurons resulted in the formulation of the term “The Glutamate-Glutamine Cycle.” In this cycle glutamate released from neurons is taken up by surrounding astrocytes, amidated by the action of glutamine synthetase to glutamine which can be transferred back to the neurons. The conversion of glutamate to glutamine is like a stealth technology, hiding the glutamate molecule which would be highly toxic to neurons due to its excitotoxic action. This series of reactions require the concerted and precise interaction of a number of enzymes and plasma membrane transporters, and this volume provides in-depth descriptions of these processes. Obviously such a series of complicated reactions may well be prone to malfunction and therefore neurological diseases are likely to be associated with such malfunction of the enzymes and transporters involved in the cycle. These aspects are also discussed in several chapters of the book. A number of leading experts in neuroscience including intermediary metabolism, enzymology and transporter physiology have contributed to this book which provides comprehensive discussions of these different aspects of the functional importance of the glutamate-glutamine cycle coupling homeostasis of glutamatergic, excitatory neurotransmission to basic aspects of brain energy metabolism. This book will be of particular importance for students as well as professionals interested in these fundamental processes involved in brain function and dysfunction.

The Gaba Receptors, Third Edition, presents a critical appraisal of our current understanding of the molecular, behavioral, biochemical, clinical, and pharmacological properties of GABA receptors. Emphasis is placed on exploring cutting-edge findings on the structureal properties of receptor sites, mechanisms of receptor expression, chemical agents that differentiate receptor subtypes, and phenotypes displayed by GABA receptor null mice. Chapters in this updated and expanded edition examine such topics as GABA receptor subypes, trafficking postsynaptic GABA receptors, GABA receptor mutations associated with idiopathic generalized epilepsies and febrile seizures, and GABA receptors as a potential therapeutic target.

This book collates the contributions of a selected number of neuroscientists that are interested in the molecular, preclinical, and clinical aspects of neurotransmission research. The seven chapters in this book address the latest research/review data related to GABA/glutamate system's organization and function, the structure of receptors, subtypes and their ligands, as well as the translational approach and clinical implications. The book offers readers a rich collection of data regarding current and future applications of GABA and glutamate neurotransmission, including promising research strategies and potential clinical benefits.

Brain aminergic pathways are organized in parallel and interacting systems, which support a range of functions, from homoeostatic regulations to cognitive, and motivational processes. Despite overlapping functional influences, dopamine, serotonin, noradrenaline and histamine systems provide different contributions to these processes. The histaminergic system, long ignored as a major regulator of the sleep-wake cycle, has now been fully acknowledged also as a major coordinator of attention, learning and memory, decision making. Although histaminergic neurons project widely to the whole brain, they are functionally heterogeneous, a feature which may provide the substrate for differential regulation, in a region-specific manner, of other neurotransmitter systems. Neurochemical preclinical studies have clearly shown that histamine interacts and modulates the release of neurotransmitters that are recognized as major modulators of cognitive processing and motivated behaviours. As a consequence, the histamine system has been proposed as a therapeutic target to treat sleep-wake disorders and cognitive dysfunctions that accompany neurodegenerative and neuroinflammatory pathologies. Last decades have witnessed an unexpected explosion of interest in brain histamine system, as new receptors have been discovered and selective ligands synthesised. Nevertheless, the complete picture of the histamine systems fine-tuning and its orchestration with other pathways remains rather elusive. This Research Topic is intended to offer an inter-disciplinary forum that will improve our current understanding of the role of brain histamine and provide the fundamentals necessary to drive innovation in clinical practice and to improve the management and treatment of neurological disorders.

Three distinct types of contractions perform colonic motility functions. Rhythmic phasic contractions (RPCs) cause slow net distal propulsion with extensive mixing/turning over. Infrequently occurring giant migrating contractions (GMCs) produce mass movements. Tonic contractions aid RPCs in their motor function. The spatiotemporal patterns of these contractions differ markedly. The amplitude and distance of propagation of a GMC are several-fold larger than those of an RPC. The enteric neurons and smooth muscle cells are the core regulators of all three types of contractions. The regulation of contractions by these mechanisms is modifiable by extrinsic factors: CNS, autonomic neurons, hormones, inflammatory mediators, and stress mediators. Only the GMCs produce descending inhibition, which accommodates the large bolus being propelled without increasing muscle tone. The strong compression of the colon wall generates afferent signals that are below nociceptive threshold in healthy subjects. However, these signals become nociceptive; if the amplitudes of GMCs increase, afferent nerves become hypersensitive, or descending inhibition is impaired. The GMCs also provide the force for rapid propulsion of feces and descending inhibition to relax the internal anal sphincter during defecation. The dysregulation of GMCs is a major factor in colonic motility disorders: irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and diverticular disease (DD). Frequent mass movements by GMCs cause diarrhea in diarrhea predominant IBS, IBD, and DD, while a decrease in the frequency of GMCs causes constipation. The GMCs generate the afferent signals for intermittent short-lived episodes of abdominal cramping in these disorders. Epigenetic dysregulation due to adverse events in early life is one of the major factors in generating the symptoms of IBS in adulthood.