scholarly journals Spatial and Temporal Dynamics in the Ionic Driving Force for GABAAReceptors

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
R. Wright ◽  
J. V. Raimondo ◽  
C. J. Akerman
Keyword(s):  
Driving Force ◽  
Neural Circuit ◽  
Temporal Dynamics ◽  
Spatial And Temporal Dynamics ◽  
Mature Brain ◽  
Gabaergic Synapses ◽  
Circuit Development ◽  
And Function ◽  
Activity Dependent

It is becoming increasingly apparent that the strength of GABAergic synaptic transmission is dynamic. One parameter that can establish differences in the actions of GABAergic synapses is the ionic driving force for the chloride-permeable GABAAreceptor (GABAAR). Here we review some of the sophisticated ways in which this ionic driving force can vary within neuronal circuits. This driving force for GABAARs is subject to tight spatial control, with the distribution of Cl−transporter proteins and channels generating regional variation in the strength of GABAAR signalling across a single neuron. GABAAR dynamics can result from short-term changes in their driving force, which involve the temporary accumulation or depletion of intracellular Cl−. In addition, activity-dependent changes in the expression and function of Cl−regulating proteins can result in long-term shifts in the driving force for GABAARs. The multifaceted regulation of the ionic driving force for GABAARs has wide ranging implications for mature brain function, neural circuit development, and disease.

Surface-groundwater interactions in karst: overview, concept and mapping

2021 ◽  
Author(s):  
Natasa Ravbar ◽  
Cyril Mayaud ◽  
Matej Blatnik ◽  
Metka Petrič
Keyword(s):  
Environmental Changes ◽  
Temporal Dynamics ◽  
Field Measurements ◽  
Spatial Dimension ◽  
Karst Aquifers ◽  
Wetland Ecosystems ◽  
Spatial And Temporal Dynamics ◽  
Ecohydrological Processes

<p>Under special meteorological and hydrological circumstances, shallow karst areas and karst poljes may experience surface water overflow. As a result, surface- groundwater interaction occurs usually creating intermittent lakes. Although human settlements and activities have traditionally adapted to these natural conditions, extensive temporary floods are classified among the most common natural disasters in karst. On the other hand, intermittent lakes are considered as natural reservoirs of excess recharge and good flood regulators in the lower parts of river basins. Due to specific ecohydrological processes and environmental conditions, these areas host unique wetland ecosystems with high levels of biodiversity and provide various ecosystem services, such as ecological productivity, photosynthesis and carbon storage. Given the dynamic nature of hydrological processes in karst aquifers, a distinctive feature of the phenomena described is its high variability of occurrence and duration. Therefore, the identification, characterization as well as the determination of the spatial dimension of flood levels is a challenging task. Focusing on the Slovenian karst, a literature review and analysis of topographical and hydrological data of the selected study areas was conducted. The hydrological analyses were based on long-term monitoring data from Slovenian Environmental Agency and partly on the authors' own database of field measurements and knowledge of the areas concerned. Consequently, the conceptual framework and the key criterion for the determination and recording of areas subject to temporary flooding were developed. A systematic survey reveals the significance of the extent, duration and frequency of flooding. Evaluation results are useful to designers of various water policies and management mechanisms for flood mitigation and protection of special habitats. Observing trends in the spatial and temporal dynamics of flood levels is also valuable for understanding how and to what extent karst aquifers are vulnerable to environmental changes. Finally, the analyses also enable prediction of the effects of these changes on other parts of the environment (e.g., hydrophilic habitats).</p>

scholarly journals Spatial and Temporal Dynamics of Electrical and Photosynthetic Activity and the Content of Phytohormones Induced by Local Stimulation of Pea Plants

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1364
Author(s):  
Maria Ladeynova ◽  
Maxim Mudrilov ◽  
Ekaterina Berezina ◽  
Dmitry Kior ◽  
Marina Grinberg ◽  
...  
Keyword(s):  
Photosynthetic Activity ◽  
Temporal Dynamics ◽  
Response Analysis ◽  
Vascular Bundles ◽  
Variation Potential ◽  
Spatial And Temporal Dynamics ◽  
Two Phases ◽  
Local Stimulation ◽  
Transpiration Suppression

A local leaf burning causes variation potential (VP) propagation, a decrease in photosynthesis activity, and changes in the content of phytohormones in unstimulated leaves in pea plants. The VP-induced photosynthesis response develops in two phases: fast inactivation and long-term inactivation. Along with a decrease in photosynthetic activity, there is a transpiration suppression in unstimulated pea leaves, which corresponds to the long-term phase of photosynthesis response. Phytohormone level analysis showed an increase in the concentration of jasmonic acid (JA) preceding a transpiration suppression and a long-term phase of the photosynthesis response. Analysis of the spatial and temporal dynamics of electrical signals, phytohormone levels, photosynthesis, and transpiration activity showed the most pronounced changes in the more distant leaf from the area of local stimulation. The established features are related to the architecture of the vascular bundles in the pea stem.

scholarly journals The Many Forms and Functions of Long Term Plasticity at GABAergic Synapses

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Arianna Maffei
Keyword(s):  
Synaptic Plasticity ◽  
Neural Circuits ◽  
Dynamic Range ◽  
Theoretical Work ◽  
Long Term Potentiation ◽  
Inhibitory Neurons ◽  
Gabaergic Synapses ◽  
The Many ◽  
And Function

On February 12th 1973, Bliss and Lomo submitted their findings on activity-dependent plasticity of glutamatergic synapses. After this groundbreaking discovery, long-term potentiation (LTP) and depression (LTD) gained center stage in the study of learning, memory, and experience-dependent refinement of neural circuits. While LTP and LTD are extensively studied and their relevance to brain function is widely accepted, new experimental and theoretical work recently demonstrates that brain development and function relies on additional forms of plasticity, some of which occur at nonglutamatergic synapses. The strength of GABAergic synapses is modulated by activity, and new functions for inhibitory synaptic plasticity are emerging. Together with excitatory neurons, inhibitory neurons shape the excitability and dynamic range of neural circuits. Thus, the understanding of inhibitory synaptic plasticity is crucial to fully comprehend the physiology of brain circuits. Here, I will review recent findings about plasticity at GABAergic synapses and discuss how it may contribute to circuit function.

scholarly journals Timing and Duration of Gbx2 Expression Delineates Thalamocortical and Dopaminergic Medial Forebrain Bundle Circuitry

2019 ◽  
Author(s):  
Elizabeth Normand ◽  
Catherine Browning ◽  
Mark Zervas
Keyword(s):  
Gene Expression ◽  
Medial Forebrain Bundle ◽  
Neural Circuit ◽  
Temporal Dynamics ◽  
Neuronal Cell ◽  
Cell Types ◽  
Dopamine Neurons ◽  
Genetic Lineage ◽  
Thalamocortical Axons ◽  
Circuit Development

SUMMARYGene expression is a dynamic process, which is highly coordinated during development to ensure the proper allocation and identity of neuronal cell types within the brain. Equally important during neurodevelopment is how cohorts of neurons establish axonal projections that innervate terminal target sites. We sought to bridge the temporal dynamics of gene expression, within a specific genetic lineage, to the establishment of neuronal circuits derived from cohorts of the lineage-specific progenitors. A central goal was to be able to accomplish genetic inducible circuit mapping non-invasively and with commonly available CreER/loxP technology. Specifically, we genetically marked thalamic neuron progenitors that expressed the transcription factor Gbx2 at an early embryonic stage and tracked the formation of lineage-derived thalamocortical axons during embryogenesis. We then assessed the neural circuitry at an early postnatal stage. We show that the temporal specificity of lineage marking provides a high degree of clarity for following neural circuit development. We also determined that the onset and duration of gene expression can delineate subsets of neural circuits derived from a common lineage. For example, we uncovered a novel contribution of Gbx2-expressing progenitors to midbrain dopamine neurons and dopaminergic axons of the medial forebrain bundle. We anticipate that this system can be instructive in elucidating changes in neural circuit development in both normal development and in mutant mice in which neural circuit formation is altered.

scholarly journals Dinámica espacio-temporal del esfuerzo en una pesquería de buceo artesanal multiespecífica y sus efectos en la variabilidad de las capturas: Implicaciones para el manejo sostenible

2014 ◽  
Vol 62 (4) ◽  
pp. 1565 ◽  
Author(s):  
Helven Naranjo Madrigal ◽  
Silvia Salas Márquez
Keyword(s):  
Fisheries Management ◽  
Pacific Coast ◽  
Temporal Dynamics ◽  
Fishing Effort ◽  
The North ◽  
Fishing Strategies ◽  
Personal Consumption ◽  
Spatial And Temporal Dynamics ◽  
The North Pacific

Artisanal diving fisheries are a source of income, employment and food security of coastal areas in many countries. Understanding the dynamics of these fisheries, including the spatial and temporal dynamics of fishing effort, gears and species can help to address the challenges involved in fisheries management. We aimed to analyze the differences in fishing strategies undertaken by fishers that use two different diving methods (hookah and free diving), and the conditions and their potential impacts on catches when adjustments to those strategies are applied over time. For this, detailed information of fishing operations from artisanal boats in the North Pacific coast of Costa Rica was analyzed in two fishing seasons (2007-2008 and 2011-2012). Data were collected by onboard observers (fishing site, fishing time, species composition, depth and visibility). Additionally, interviews with divers were applied to obtain information of price per species, species volume and fishing operations. From the total number of trips during both seasons, hookah diving was represented by a sample size of 70.5%, while free diving, with a sample of 69.5%. More than 15 species were identified in each fishing season. Nevertheless, three categories had substantial contributions in both seasons with differences in the proportions for each case: green lobster (<em>Panulirus gracilis</em>), octopus (<em>Octopus</em> sp.) and parrotfish (<em>Scarus perrico</em> and <em>S. ghobban</em>). It is worth noting that an important proportion of catch was retained by fishers for personal consumption purposes, including species of high commercial value. Additional night diving activity, increased the number of dives from one season to another. Besides, cooperation processes in free diving fishing operations, and changes in fishing effort between seasons, defined important changes in fishing strategies. Potential causes of changes in fishing strategies and the implications for management to ensure the sustainability of these fisheries in the long term are discussed.

scholarly journals Rebound in functional distinctiveness following warming and reduced fishing in the North Sea

2021 ◽  
Vol 288 (1942) ◽  
pp. 20201600
Author(s):  
Juliette Murgier ◽  
Matthew McLean ◽  
Anthony Maire ◽  
David Mouillot ◽  
Nicolas Loiseau ◽  
...  
Keyword(s):  
North Sea ◽  
Temporal Dynamics ◽  
Distinct Species ◽  
Common Species ◽  
Fishing Pressure ◽  
The North ◽  
Spatial And Temporal Dynamics ◽  
Recent Climate ◽  
The North Sea

Functionally distinct species (i.e. species with unique trait combinations in the community) can support important ecological roles and contribute disproportionately to ecosystem functioning. Yet, how functionally distinct species have responded to recent climate change and human exploitation has been widely overlooked. Here, using ecological traits and long-term fish data in the North Sea, we identified functionally distinct and functionally common species, and evaluated their spatial and temporal dynamics in relation to environmental variables and fishing pressure. Functionally distinct species were characterized by late sexual maturity, few, large offspring, and high parental care, many being sharks and skates that play critical roles in structuring food webs. Both functionally distinct and functionally common species increased in abundance as ocean temperatures warmed and fishing pressure decreased over the last three decades; however, functionally distinct species increased throughout the North Sea, but primarily in southern North Sea where fishing was historically most intense, indicating a rebound following fleet decommissioning and reduced harvesting. Yet, some of the most functionally distinct species are currently listed as threatened by the IUCN and considered highly vulnerable to fishing pressure. Alarmingly these species have not rebounded. This work highlights the relevance and potential of integrating functional distinctiveness into ecosystem management and conservation prioritization.

scholarly journals Persistent Synaptic Activity Produces Long-Lasting Enhancement of Endocannabinoid Modulation and Alters Long-Term Synaptic Plasticity

2007 ◽  
Vol 97 (6) ◽  
pp. 4386-4389 ◽  
Author(s):  
Ping Jun Zhu ◽  
David M. Lovinger
Keyword(s):  
Low Frequency ◽  
Long Term Potentiation ◽  
Information Storage ◽  
Synaptic Activity ◽  
Inhibitory Synapses ◽  
Term Potentiation ◽  
Hippocampal Ca1 ◽  
Gabaergic Synapses ◽  
Activity Dependent

Learning and memory are thought to involve activity-dependent changes in synaptic efficacy such as long-term potentiation (LTP) and long-term depression (LTD). Recent studies have indicated that endocannabinoid-dependent modulation of inhibitory transmission facilitates induction of hippocampal LTP and that endocannabinoids play a key role in certain forms of LTD. Here, we show that repetitive low-frequency synaptic stimulation (LFS) produces persistent up-regulation of endocannabinoid signaling at hippocampal CA1 GABAergic synapses. This LFS also produces LTD of inhibitory synapses and facilitates LTP at excitatory, glutamatergic synapses. These endocannabinoid-mediated plastic changes could contribute to information storage within the brain.

scholarly journals Developmental synaptic regulator, TWEAK/Fn14 signaling, is a determinant of synaptic function in models of stroke and neurodegeneration

2021 ◽  
Vol 118 (6) ◽  
pp. e2001679118
Author(s):  
Dávid Nagy ◽  
Katelin A. Ennis ◽  
Ru Wei ◽  
Susan C. Su ◽  
Christopher A. Hinckley ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Neural Circuit ◽  
Hippocampal Slices ◽  
Visual Development ◽  
Synaptic Function ◽  
Synaptic Physiology ◽  
Mature Brain ◽  
Circuit Development ◽  
Basal Synaptic Transmission

Identifying molecular mediators of neural circuit development and/or function that contribute to circuit dysfunction when aberrantly reengaged in neurological disorders is of high importance. The role of the TWEAK/Fn14 pathway, which was recently reported to be a microglial/neuronal axis mediating synaptic refinement in experience-dependent visual development, has not been explored in synaptic function within the mature central nervous system. By combining electrophysiological and phosphoproteomic approaches, we show that TWEAK acutely dampens basal synaptic transmission and plasticity through neuronal Fn14 and impacts the phosphorylation state of pre- and postsynaptic proteins in adult mouse hippocampal slices. Importantly, this is relevant in two models featuring synaptic deficits. Blocking TWEAK/Fn14 signaling augments synaptic function in hippocampal slices from amyloid-beta–overexpressing mice. After stroke, genetic or pharmacological inhibition of TWEAK/Fn14 signaling augments basal synaptic transmission and normalizes plasticity. Our data support a glial/neuronal axis that critically modifies synaptic physiology and pathophysiology in different contexts in the mature brain and may be a therapeutic target for improving neurophysiological outcomes.

scholarly journals The Drosophila Larval Locomotor Circuit Provides a Model to Understand Neural Circuit Development and Function

2021 ◽  
Vol 15 ◽  
Author(s):  
Iain Hunter ◽  
Bramwell Coulson ◽  
Aref Arzan Zarin ◽  
Richard A. Baines
Keyword(s):  
Neural Circuits ◽  
Neural Circuit ◽  
Fruit Fly ◽  
Model Organisms ◽  
Generic Model ◽  
Critical Periods ◽  
Neuroscience Research ◽  
Circuit Development ◽  
And Function ◽  
Model Circuit

It is difficult to answer important questions in neuroscience, such as: “how do neural circuits generate behaviour?,” because research is limited by the complexity and inaccessibility of the mammalian nervous system. Invertebrate model organisms offer simpler networks that are easier to manipulate. As a result, much of what we know about the development of neural circuits is derived from work in crustaceans, nematode worms and arguably most of all, the fruit fly, Drosophila melanogaster. This review aims to demonstrate the utility of the Drosophila larval locomotor network as a model circuit, to those who do not usually use the fly in their work. This utility is explored first by discussion of the relatively complete connectome associated with one identified interneuron of the locomotor circuit, A27h, and relating it to similar circuits in mammals. Next, it is developed by examining its application to study two important areas of neuroscience research: critical periods of development and interindividual variability in neural circuits. In summary, this article highlights the potential to use the larval locomotor network as a “generic” model circuit, to provide insight into mammalian circuit development and function.

Sign in / Sign up

Export Citation Format

Share Document