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Dynamics of cyclic nucleotide signaling in neurons

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889196463 Year: Pages: 92 DOI: 10.3389/978-2-88919-646-3 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Neurology
Added to DOAB on : 2016-08-16 10:34:25
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Abstract

Cyclic nucleotides control a number of neuronal properties including neuronal differentiation, pathfinding, regulation of excitability and synaptic transmission, and control of gene expression. Signaling events mediated by cAMP or cGMP are transient and take place within the complex 3-dimensional structure of the neuronal cell. Signaling events happen on the time scale of seconds to minutes and the biological significance of the temporal dimension remains poorly understood. Structural features of neurons (dendritic spines and branches, cell body, nucleus, axon…) as well as AKAPs and other scaffolding proteins that keep signaling enzymes together and form "signaling microdomains", are critical spatial determinants of signal integration. Finally, the types of enzymes involved in signal integration, which are expressed as a number of different types and splice variants, yield another dimension that determines signal integration properties. Biosensor imaging provides direct temporal and spatial measurement of intracellular signals. This novel approach, together with more conventional methods such as biochemistry, electrophysiology, and modeling, now provide a better understanding of the spatial and temporal features of cyclic nucleotide signal integration in living neurons. This topic aims at providing a better understanding of how neurons are "making sense" of cyclic nucleotide signaling in living neurons.

Structure-Related Intrinsic Electrical States and Firing Patterns of Neurons With Active Dendrites

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889456086 Year: Pages: 296 DOI: 10.3389/978-2-88945-608-6 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Neurology
Added to DOAB on : 2019-01-23 14:53:43
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Activity of the multi-functional networked neurons depends on their intrinsic states and bears both cell- and network-defined features. Firing patterns of a neuron are conventionally attributed to spatial-temporal organization of inputs received from the network-mates via synapses, in vast majority dendritic. This attribution reflects widespread views of the within-cell job sharing, such that the main function of the dendrites is to receive signals and deliver them to the axo-somatic trigger zone, which actually generates the output pattern. However, these views are now revisited due to finding of active, non-linear properties of the dendritic membrane practically in neurons of practically all explored types. Like soma and axon, the dendrites with active membrane are able to generate self-maintained, propagating depolarizations and thus share intrinsic pattern-forming role with the trigger zone. Unlike the trigger zone, the dendrites have complex geometry, which is subject to developmental, activity-dependent, or neurodegenerative changes. Structural features of the arborization inevitably impact on electrical states and cooperative behavior of its constituting parts at different levels of organization, from sub-trees and branches to voltage- and ligand-gated ion channels populating the dendritic membrane. More than two decades of experimental and computer simulation studies have brought numerous phenomenological demonstrations of influence of the dendritic structure on neuronal firing patterns. A necessary step forward is to comprehend these findings and build a firm theoretical basis, including quantitative relationships between geometrical and electrical characteristics determining intrinsic activity of neurons. The articles in this eBook represent progress achieved in a broad circle of laboratories studied various aspects of structure and function of the neuronal dendrites. The authors elucidate new details of dendritic mechanisms underlying intrinsic activity patterns in neurons and highlight important questions that remain open in this important domain of cellular and computational neuroscience.

Dinophysis Toxins: Distribution, Fate in Shellfish and Impacts

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ISBN: 9783039213634 9783039213641 Year: Pages: 376 DOI: 10.3390/books978-3-03921-364-1 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Medicine (General) --- Public Health
Added to DOAB on : 2019-12-09 11:49:15
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Several species of Dinophysis produce one or two groups of lipophilic toxins: okadaic acid (OA) and its derivatives; or the dinophysistoxins (DTXs) (also known as diarrhetic shellfish poisons or DSP toxins) and pectenotoxins (PTXs). DSP toxins are potent inhibitors of protein phosphatases, causing gastrointestinal intoxication in consumers of contaminated seafood. Forty years after the identification of Dinophysis as the causative agent of DSP in Japan, contamination of filter feeding shellfish exposed to Dinophysis blooms is recognized as a problem worldwide. DSP events affect public health and cause considerable losses to the shellfish industry. Costly monitoring programs are implemented in regions with relevant shellfish production to prevent these socioeconomic impacts. Harvest closures are enforced whenever toxin levels exceed regulatory limits (RLs). Dinophysis species are kleptoplastidic dinoflagellates; they feed on ciliates (Mesodinium genus) that have previously acquired plastids from cryptophycean (genera Teleaulax, Plagioselmis, and Geminigera) nanoflagellates. The interactions of Dinophysis with different prey regulate their growth and toxin production. When Dinophysis cells are ingested by shellfish, their toxins are partially biotransformed and bioaccumulated, rendering the shellfish unsuitable for human consumption. DSP toxins may also affect shellfish metabolism. This book covers diverse aspects of the abovementioned topics—from the laboratory culture of Dinophysis and the kinetics of uptake, transformation, and depuration of DSP toxins in shellfish to Dinophysis population dynamics, the monitoring and regulation of DSP toxins, and their impact on the shellfish industry in some of the aquaculture regions that are traditionally most affected, namely, northeastern Japan, western Europe, southern Chile, and New Zealand.

Keywords

harmful algal bloom --- Diarrheic Shellfish Poisoning --- okadaic acid --- toxin accumulation --- toxin vectors --- trophic transfer --- Brazil --- diarrhetic shellfish toxins (DST) --- Mytilus galloprovincialis --- DST accumulation --- DST esterification --- suspended particulate matter (SPM) --- harmful algal blooms --- okadaic acid --- Argopecten irradians --- transcriptomic response --- deep sequencing --- pectenotoxins --- surf clam --- accumulation --- biotransformation --- depuration --- diarrhetic shellfish toxins --- accumulation --- dinophysistoxin --- Japanese scallop --- dinophysis --- LC/MS/MS --- statistical analysis --- Dinophysis --- HAB monitoring --- DSP toxins --- aquaculture --- shellfish toxicity --- human health --- time-series --- seasonality --- Scotland --- DSP toxins --- bivalves --- mussel --- resistance --- RNA-Seq --- qPCR --- metabolism --- defense --- immunity --- DSP toxins --- pectenotoxins --- Dinophysis acuminata --- Mesodinium rubrum --- bacterial community --- high throughput sequencing --- diarrhetic shellfish toxins --- Dinophysis --- wild harvest --- bivalve shellfish --- pipis (Plebidonax deltoides) --- Sydney rock oyster (Saccostrea glomerata) --- okadaic acid --- pectenotoxins --- Dinophysis toxins --- accumulation --- digestion --- biotransformation --- compartmentalization --- depuration --- kinetics --- Dinophysis --- diarrhetic shellfish poisoning --- marine toxins --- pectenotoxin --- okadaic acid --- dinophysistoxin --- okadaic acid --- pectenotoxins --- Dinophysis --- D. acuminata-complex --- D. caudata --- Argopecten purpuratus --- Dinophysis --- Mesodinium --- cryptophytes --- predator-prey preferences --- Diarrhetic Shellfish Toxins (DST) --- pectenotoxins (PTXs) --- mixotrophic cultures --- mass culture conditions --- Dinophysis acuminata --- Protoceratium reticulatum --- Reloncaví Fjord --- OMI analysis --- WitOMI analysis --- Mesodinium cf. rubrum --- El Niño Southern Oscillation --- Southern Annual Mode --- Dinophysis acuta --- Dinophysis acuminata --- DSP --- physical–biological interactions --- niche partitioning --- climatic anomaly --- Dinophysis acuminata --- Mesodinium rubrum --- lysate --- organic matter --- diarrhetic shellfish poisoning --- okadaic acid --- dinophysistoxin --- pectenotoxins --- dinophysis --- DSP --- toxins --- OA --- DTX-2 --- PTXs --- Dinophysis acuminata --- dinophysistoxins --- pectenotoxins --- Port Underwood --- New Zealand --- Dinophysis --- Diarrhetic shellfish toxins --- marine biotoxins --- blooms --- n/a

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