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Neuronal and glial structural plasticity induced by drugs of abuse

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195985 Year: Pages: 90 DOI: 10.3389/978-2-88919-598-5 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Therapeutics
Added to DOAB on : 2016-03-10 08:14:32
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Drugs of abuse induce a host of alterations in brain structure and function, ranging from changes in gene expression and epigenetic processes to aberrant synaptic plasticity to volumetric changes in discrete brain regions. These alterations can be drug class-specific, and are not confined to neurons, as drugs of abuse also induce molecular and cellular alterations in various glial cell types such as astrocytes and microglia. The phenomenon of drug-induced plasticity includes changes in dendritic branching and architecture, dendritic spine density and morphology, astrocyte-neuronal interactions, dysregulation of glutamatergic and GABAergic signaling, and alterations in myelination or microglial phenotype. This drug-induced "rewiring" of the brain at numerous levels can contribute to the development, maintenance, and persistence of the addicted state, as well as associated deficits in normal cognitive functioning. The aim of this Research Topic is to collect recent and important findings related to the structural alterations produced by drug of abuse in neurons, glial, and other cell types of the central nervous system.

Keywords

plasticity --- Dendrite --- Spine --- Glutamate --- Dopamine --- GABA --- Neuron --- glia --- astrocyte --- Addiction

At The Top of the Interneuronal Pyramid - Calretinin Expressing Cortical Interneurons

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197088 Year: Pages: 102 DOI: 10.3389/978-2-88919-708-8 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2016-04-07 11:22:02
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It is in general well appreciated that the cortical interneurons play various important roles in cortical neuronal networks both in normal and pathological states. Based on connectivity pattern, developmental, morphological and electrophysiological properties, distinct subgroups of GABAergic interneurons can be differentiated in the neocortex as well as in the hippocampal formation. In this E-Book, we are focusing our attention on inhibitory interneurons expressing calcium-binding protein calretinin (CR). The aim of the E-Book is to consolidate the knowledge about this interneuronal population and to inspire further research on the function and malfunction of these neurons, which – functionally – seem to stand "at the top of the pyramid" of cortical interneuronal types.

Inhibitory Function in Auditory Processing

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889196678 Year: Pages: 231 DOI: 10.3389/978-2-88919-667-8 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Neurology
Added to DOAB on : 2016-08-16 10:34:25
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There seems little doubt that from the earliest evolutionary beginnings, inhibition has been a fundamental feature of neuronal circuits - even the simplest life forms sense and interact with their environment, orienting or approaching positive stimuli while avoiding aversive stimuli. This requires internal signals that both drive and suppress behavior. Traditional descriptions of inhibition sometimes limit its role to the suppression of action potential generation. This view fails to capture the vast breadth of inhibitory function now known to exist in neural circuits. A modern perspective on inhibitory signaling comprises a multitude of mechanisms. For example, inhibition can act via a shunting mechanism to speed the membrane time constant and reduce synaptic integration time. It can act via G-protein coupled receptors to initiate second messenger cascades that influence synaptic strength. Inhibition contributes to rhythm generation and can even activate ion channels that mediate inward currents to drive action potential generation. Inhibition also appears to play a role in shaping the properties of neural circuitry over longer time scales. Experience-dependent synaptic plasticity in developing and mature neural circuits underlies behavioral memory and has been intensively studied over the past decade. At excitatory synapses, adjustments of synaptic efficacy are regulated predominantly by changes in the number and function of postsynaptic glutamate receptors. There is, however, increasing evidence for inhibitory modulation of target neuron excitability playing key roles in experience-dependent plasticity. One reason for our limited knowledge about plasticity at inhibitory synapses is that in most circuits, neurons receive convergent inputs from disparate sources. This problem can be overcome by investigating inhibitory circuits in a system with well-defined inhibitory nuclei and projections, each with a known computational function. Compared to other sensory systems, the auditory system has evolved a large number of subthalamic nuclei each devoted to processing distinct features of sound stimuli. This information once extracted is then re-assembled to form the percept the acoustic world around us. The well-understood function of many of these auditory nuclei has enhanced our understanding of inhibition's role in shaping their responses from easily distinguished inhibitory inputs. In particular, neurons devoted to processing the location of sound sources receive a complement of discrete inputs for which in vivo activity and function are well understood. Investigation of these areas has led to significant advances in understanding the development, physiology, and mechanistic underpinnings of inhibition that apply broadly to neuroscience. In this series of papers, we provide an authoritative resource for those interested in exploring the variety of inhibitory circuits and their function in auditory processing. We present original research and focused reviews touching on development, plasticity, anatomy, and evolution of inhibitory circuitry. We hope our readers will find these papers valuable and inspirational to their own research endeavors.

Intellectual Disabilities in Down Syndrome from Birth and throughout Life: Assessment and Treatment

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889450459 Year: Pages: 179 DOI: 10.3389/978-2-88945-045-9 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2017-07-06 13:27:36
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Research on the multiple aspects of cognitive impairment in Down syndrome (DS), from genes to behavior to treatment, has made tremendous progress in the last decade. The study of congenital intellectual disabilities such as DS is challenging since they originate from the earliest stages of development and both the acquisition of cognitive skills and neurodegenerative pathologies are cumulative. Comorbidities such as cardiac malformations, sleep apnea, diabetes and dementia are frequent in the DS population, as well, and their increased risk provides a means of assessing early stages of these pathologies that is relevant to the general population. Notably, persons with DS will develop the histopathology of Alzheimer’s disease (formation of neuritic plaques and tangles) and are at high risk for dementia, something that cannot be predicted in the population at large. Identification of the gene encoding the amyloid precursor protein, its localization to chromosome 21 in the 90’s and realization that all persons with DS develop pathology identified this as an important piece of the amyloid cascade hypothesis in Alzheimer’s disease. Awareness of the potential role of people with DS in understanding progression and treatment as well as identification of genetic risk factors and also protective factors for AD is reawakening. For the first time since DS was recognized, major pharmaceutical companies have entered the search for ameliorative treatments, and phase II clinical trials to improve learning and memory are in progress. Enriched environment, brain stimulation and alternative therapies are being tested while clinical assessment is improving, thus increasing the chances of success for therapeutic interventions. Researchers and clinicians are actively pursuing the possibility of prenatal treatments for many conditions, an area with a huge potential impact for developmental disorders such as DS. Our goal here is to present an overview of recent advances with an emphasis on behavioral and cognitive deficits and how these issues change through life in DS. The relevance of comorbidities to the end phenotypes described and relevance of pharmacological targets and possible treatments will be considerations throughout.Research on the multiple aspects of cognitive impairment in Down syndrome (DS), from genes to behavior to treatment, has made tremendous progress in the last decade. The study of congenital intellectual disabilities such as DS is challenging since they originate from the earliest stages of development and both the acquisition of cognitive skills and neurodegenerative pathologies are cumulative. Comorbidities such as cardiac malformations, sleep apnea, diabetes and dementia are frequent in the DS population, as well, and their increased risk provides a means of assessing early stages of these pathologies that is relevant to the general population. Notably, persons with DS will develop the histopathology of Alzheimer’s disease (formation of neuritic plaques and tangles) and are at high risk for dementia, something that cannot be predicted in the population at large. Identification of the gene encoding the amyloid precursor protein, its localization to chromosome 21 in the 90’s and realization that all persons with DS develop pathology identified this as an important piece of the amyloid cascade hypothesis in Alzheimer’s disease. Awareness of the potential role of people with DS in understanding progression and treatment as well as identification of genetic risk factors and also protective factors for AD is reawakening. For the first time since DS was recognized, major pharmaceutical companies have entered the search for ameliorative treatments, and phase II clinical trials to improve learning and memory are in progress. Enriched environment, brain stimulation and alternative therapies are being tested while clinical assessment is improving, thus increasing the chances of success for therapeutic interventions. Researchers and clinicians are actively pursuing the possibility of prenatal treatments for many conditions, an area with a huge potential impact for developmental disorders such as DS. Our goal here is to present an overview of recent advances with an emphasis on behavioral and cognitive deficits and how these issues change through life in DS. The relevance of comorbidities to the end phenotypes described and relevance of pharmacological targets and possible treatments will be considerations throughout.

MR Spectroscopy in Neuropsychiatry

Authors: --- --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889455249 Year: Pages: 90 DOI: 10.3389/978-2-88945-524-9 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Psychiatry
Added to DOAB on : 2019-01-23 14:53:42
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Neuropsychiatric disorders, covering both psychotic and depressive disorders, but also autism and attention-deficit hyperactivity disorder (ADHD), are characterized by abnormal behavior and brain structure. Accumulating evidence suggests that altered neurochemistry plays a role in these disorders and may have a causal relationship with the observed behavioral and structural abnormalities. To improve the understanding of neurochemical anomalies and (patho)physiological changes in psychiatric conditions, in vivo assessment of the affected tissue, the brain, is wanted and needed. Magnetic resonance spectroscopy (MRS) is a non-invasive technique which allows in vivo assessment of the molecular composition of brain tissues and identification of metabolites involved in physiological and pathological processes, which is otherwise virtually impossible. Only in the last decade with the development of high field MR methodologies, MRS has become sensitive enough for broader use in clinical studies. The implications are many, but proper guidance and elucidation of the pros and cons for the specific methods is needed to optimally exploit the potential.This Research Topic updates the reader on the possibilities and pitfalls of MRS today and highlights methodologies and applications for the future.

New Perspectives in Neurosteroids action: a Special Player Allopregnanolone

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195558 Year: Pages: 86 DOI: 10.3389/978-2-88919-555-8 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2016-01-19 14:05:46
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Early in the 80’s date the first observations on the existence of hormonal steroids that may be synthesized and act in the nervous system. In order to refer to these endogenous steroids, proved important to control both central and peripheral nervous system, it was proposed the term “neurosteroids” (NSs). Over the years, their importance in regulating the physiological functions of neuronal and glial cells increased progressively. These steroids can be involved in several pathophysiological conditions such as depression, anxiety, premenstrual syndrome (PMS), schizophrenia and Alzheimer disease. Among the different classes of NSs, the progestagens revealed particularly important. The progesterone metabolite 5a-pregnan-3a-ol-20-one, also named tetrahydroprogesterone or allopregnanolone (ALLO) was one of the first most important steroid that was originally shown to act as neurosteroid. ALLO is synthesized through the action of the 5aR-3a-HSD, which converts P into DHP and subsequently, via a bidirectional reaction, into ALLO. NSs exert complex effects in the nervous system through ‘classic’, genomic, and ‘non-classic’, non-genomic actions. ALLO displays a rapid ‘non-genomic’ effect, which mainly involves the potent modulation of the GABA type A (GABA-A) receptor function. Recently a membrane receptor has been identified as target for ALLO effects, i.e. the membrane progesterone receptors (mPRs) that are able to activate a signalling cascade through G protein dependent mechanisms. By these ways, ALLO is able to modulate several cell functions, acting as neurogenic molecule on neural progenitor cells, as well as by activating proliferation and differentiation of glial cells in the central and peripheral nervous system. In this topic, we review the most recent acquisitions in the field of neurosteroids, focusing our attention on ALLO because its effects on the physiology of neurons and glial cells of the central and peripheral nervous system are intriguing and could potentially lead to the development of new strategies for neuroprotection and/or regeneration of injured nervous tissues and for the treatment of neuropsychiatric disorders.

Amino Acids of the Glutamate Family: Functions beyond Primary Metabolism

Authors: --- --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889199365 Year: Pages: 206 DOI: 10.3389/978-2-88919-936-5 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Botany
Added to DOAB on : 2016-01-19 14:05:46
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The life of proteins starts and ends as amino acids. In addition to the primary function as protein building blocks, amino acids serve multiple other purposes to make a plant's life worth living. This is true especially for the amino acids of the glutamate family, namely glutamate (Glu), glutamine (Gln), proline (Pro) and arginine (Arg), as well as the product of Glu decarboxylation, ?-aminobutyric acid (GABA). Synthesis, accumulation, interconversion and degradation of these five compounds contribute in many ways to the regulation of plant development and to responses to environmental challenges. Glu and Gln hold key positions as entry points and master regulators of nitrogen metabolism in plants, and have a pivotal role in the regulatory interplay between carbon and nitrogen metabolism. Pro and GABA are among the best-studied compatible osmolytes that accumulate in response to water deficit, yet the full range of protective functions is still to be revealed. Arg, with its exceptionally high nitrogen-to-carbon ratio, has long been recognized as a major storage form of organic nitrogen. Most of the enzymes involved in metabolism of the amino acids of the glutamate family in plants have been identified or can be predicted according to similarity with animal or microbial homologues. However, for some of these enzymes the detailed biochemical properties still remain to be determined in order to understand activities in vivo. Additionally, uncertainties regarding the subcellular localization of proteins and especially the lack of knowledge about intracellular transport proteins leave significant gaps in our understanding of the metabolic network connecting Glu, Gln, Pro, GABA and Arg. While anabolic reactions are distributed between the cytosol and chloroplasts, catabolism of the amino acids of the glutamate family takes place in mitochondria and has been implicated in fueling energy-demanding physiological processes such as root elongation, recovery from stress, bolting and pollen tube elongation. Exceeding the metabolic functions, the amino acids of the glutamate family were recently identified as important signaling molecules in plants. Extracellular Glu, GABA and a range of other metabolites trigger responses in plant cells that resemble the actions of Glu and GABA as neurotransmitters in animals. Plant homologues of the Glu-gated ion channels from mammals and protein kinase signaling cascades have been implicated in these responses. Pollen tube growth and guidance depend on GABA signaling and the root architecture is specifically regulated by Glu. GABA and Pro signaling or metabolism were shown to contribute to the orchestration of defense and programmed cell death in response to pathogen attacks. Pro signaling was additionally proposed to regulate developmental processes and especially sexual reproduction. Arg is tightly linked to nitric oxide (NO) production and signaling in plants, although Arg-dependent NO-synthases could still not be identified. Potentially Arg-derived polyamines constitute the missing link between Arg and NO signaling in response to stress. Taken together, the amino acids of the glutamate family emerge as important signaling molecules that orchestrate plant growth and development by integrating the metabolic status of the plant with environmental signals, especially in stressful conditions. This research topic collects contributions from different facets of glutamate family amino acid signaling or metabolism to bring together, and integrate in a comprehensive view the latest advances in our understanding of the multiple functions of Glu-derived amino acids in plants.

Astrocytic-neuronal-astrocytic Pathway Selection for Formation and Degradation of Glutamate/GABA

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889192434 Year: Pages: 168 DOI: 10.3389/978-2-88919-243-4 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Biology --- Medicine (General) --- Internal medicine
Added to DOAB on : 2015-11-16 15:44:59
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Endocrinological research early recognized the importance of intercellular interactions and realized the importance of glutamatergic and GABAergic signaling. In turn this signalling depends on elaborate interactions between astrocytes and neurons, without which neurons would be unable to produce, reuse and metabolize transmitter glutamate and GABA. Details of these subjects are described in this Research Topic by key investigators in this field. It focuses on the intricate and extremely swift pathway producing these amino acid transmitters from glucose in brain but also discusses difficulties in determining expression of some of the necessary genes in astrocytes and related processes in pancreatic islets. However, it does not discuss how closely associated astrocytes and neurons are anatomically, enabling these interactions. This is elegantly shown in this cover image, kindly provided by Professor Andreas Reichenbach (University of Leipzig, Germany).

Molecular, Cellular and Model Organism Approaches for Understanding the Basis of Neurological Disease

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889451739 Year: Pages: 183 DOI: 10.3389/978-2-88945-173-9 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2017-08-28 14:01:09
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The advent of next-generation sequencing technologies has resulted in a remarkable increase our understanding of human and animal neurological disorders through the identification of disease causing or protective sequence variants. However, in many cases, robust disease models are required to understand how changes at the DNA, RNA or protein level affect neuronal and synaptic function, or key signalling pathways. In turn, these models may enable understanding of key disease processes and the identification of new targets for the medicines of the future. This e-book contains original research papers and reviews that highlight either the impact of next-generation sequencing in the understanding of neurological disorders, or utilise molecular, cellular, and whole-organism models to validate disease-causing or protective sequence variants.

The Molecular and Cellular Basis for Parkinson's Disease

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ISBN: 9783039215485 / 9783039215492 Year: Pages: 230 DOI: 10.3390/books978-3-03921-549-2 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Medicine (General) --- Neurology
Added to DOAB on : 2019-12-09 11:49:15
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The focus on dopamine-sensitive motor symptoms, in association with the improvement of motor complications in the heterogeneous disease entity Parkinson's disease, has led to a certain standstill in research. This Special Issue provides new concepts and new ideas on the pathogenesis, genetics, and clinical maintenance of Parkinson's disease and related disorders. Not only new experimental findings, but also clinical outcomes, case series, and research on alternative, non-pharmacological therapies are included. The objective is to bridge the currently increasing gap between experimental and clinical research on Parkinson's disease and related disorders.

Keywords

epigenetics --- Parkinson’s disease --- brain --- DNA methylation --- Parkinson’s disease --- fatty acid ?-oxidation --- long-chain acylcarnitine --- Parkinson’s disease --- fatty acyls --- glycerolipids --- glycerophospholipids --- sphingolipids --- sterol lipids --- lipoproteins --- ?-synuclein-mediated pathology --- disease-modifying effects --- neuroprotection --- autophagy --- cysteinyl-dopamine --- hypochlorite --- oxidative stress --- Parkinson’s disease --- redox cycling --- Parkinson’s disease --- brain iron --- motor dysfunction --- neurometabolites --- magnetic resonance imaging --- magnetic resonance spectroscopy --- GABA --- spectroscopy --- Parkinson’s disease --- neuroinflammation --- alpha-Synuclein --- immunotherapy --- mesenchymal stem cells --- secretome --- exosomes --- Parkinson’s disease --- microRNAs --- Parkinson disease --- multiprofessional therapy --- inpatient treatment --- multimodal complex treatment --- caffeic acid --- chlorogenic acid --- rotenone --- Parkinson’s disease --- neuroprotection --- dopaminergic neuron --- myenteric plexus --- enteric glial cell --- metallothionein --- Parkinson’s disease --- microbiota --- molecular mimicry --- microbiome --- alpha-synuclein --- curli --- gut-brain axis --- neurodegeneration --- glucocerebrosidase --- Parkinson’s disease --- Gaucher’s disease --- Lewy Body Dementia --- REM sleep behavior disorders --- [123I]FP-CIT-SPECT --- DAT --- nigral cells --- Parkinson’s disease --- parkinsonisms --- cell line --- differentiation --- HOG --- immature oligodendrocyte --- Krabbe’s disease --- oligodendrocyte --- mature oligodendrocyte --- MO3.13 --- myelin --- multiple sclerosis --- schizophrenia --- SH-SY5Y

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