scholarly journals Functional Consequences of the Disturbances in the GABA-Mediated Inhibition Induced by Injuriesin the Cerebral Cortex

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Barbara Imbrosci ◽  
Thomas Mittmann
Keyword(s):  
Cortical Plasticity ◽  
Epileptiform Activity ◽  
Mammalian Brain ◽  
Negative Events ◽  
Plastic Properties ◽  
Beneficial Effects ◽  
Promising Strategy ◽  
Functional Consequences ◽  
Gathering Data ◽  
Cortical Injuries

Cortical injuries are often reported to induce a suppression of the intracortical GABAergic inhibition in the surviving, neighbouring neuronal networks. Since GABAergic transmission provides the main source of inhibition in the mammalian brain, this condition may lead to hyperexcitability and epileptiform activity of cortical networks. However, inhibition plays also a crucial role in limiting the plastic properties of neuronal circuits, and as a consequence, interventions aiming to reestablish a normal level of inhibition might constrain the plastic capacity of the cortical tissue. A promising strategy to minimize the deleterious consequences of a modified inhibitory transmission without preventing the potential beneficial effects on cortical plasticity may be to unravel distinct GABAergic signaling pathways separately mediating these positive and negative events. Here, gathering data from several recent studies, we provide new insights to better face with this “double coin” condition in the attempt to optimize the functional recovery of patients.

scholarly journals Exploring the Vital Worker Over Time – A Week-Level Study on How Positive and Negative Work Events Contribute to Affect and Sustain Work Engagement

2019 ◽  
Author(s):  
Oliver Weigelt ◽  
Antje Schmitt ◽  
Christine J. Syrek ◽  
Sandra Ohly
Keyword(s):  
Work Engagement ◽  
Negative Events ◽  
Organizational Life ◽  
Positive Events ◽  
High Frequencies ◽  
Beneficial Effects ◽  
Current Events ◽  
Work Events ◽  
Job Demands And Resources ◽  
Over Time

Although work events can be regarded as pivotal elements of organizational life, only a few studies have examined how positive and negative events relate to and combine to affect work engagement over time. Theory suggests that to better understand how current events affect work engagement (WE), we have to account for recent events that have preceded these current events. We present competing theoretical views on how recent and current work events may affect employees (e.g., getting used to a high frequency of negative events or becoming more sensitive to negative events). Although the occurrence of events implies discrete changes in the experience of work, prior research has not considered whether work events actually accumulate to sustained mid-term changes in WE. To address these gaps in the literature, we conducted a week-level longitudinal study across a period of 15 consecutive weeks among 135 employees, which yielded 849 weekly observations. While positive events were associated with higher levels of WE within the same week, negative events were not. Our results support neither satiation nor sensitization processes. However, high frequencies of negative events in the preceding week amplified the beneficial effects of positive events on WE in the current week. Growth curve analyses show that the benefits of positive events accumulate to sustain high levels of WE. WE dissipates in the absence of continuous experience of positive events. Our study adds a temporal component and informs research that has taken a feature-oriented perspective on the dynamic interplay of job demands and resources.

Activity-Dependent Structural and Functional Plasticity of Astrocyte-Neuron Interactions

2008 ◽  
Vol 88 (3) ◽  
pp. 983-1008 ◽  
Author(s):  
Dionysia T. Theodosis ◽  
Dominique A. Poulain ◽  
Stéphane H. R. Oliet
Keyword(s):  
Structural Changes ◽  
Morphological Changes ◽  
Sensory Stimulation ◽  
Morphological Plasticity ◽  
Cytoskeletal Proteins ◽  
Mammalian Brain ◽  
Cellular Mechanisms ◽  
Neuronal Interactions ◽  
Functional Consequences ◽  
Activity Dependent

Observations from different brain areas have established that the adult nervous system can undergo significant experience-related structural changes throughout life. Less familiar is the notion that morphological plasticity affects not only neurons but glial cells as well. Yet there is abundant evidence showing that astrocytes, the most numerous cells in the mammalian brain, are highly mobile. Under physiological conditions as different as reproduction, sensory stimulation, and learning, they display a remarkable structural plasticity, particularly conspicuous at the level of their lamellate distal processes that normally ensheath all portions of neurons. Distal astrocytic processes can undergo morphological changes in a matter of minutes, a remodeling that modifies the geometry and diffusion properties of the extracellular space and relationships with adjacent neuronal elements, especially synapses. Astrocytes respond to neuronal activity via ion channels, neurotransmitter receptors, and transporters on their processes; they transmit information via release of neuroactive substances. Where astrocytic processes are mobile then, astrocytic-neuronal interactions become highly dynamic, a plasticity that has important functional consequences since it modifies extracellular ionic homeostasis, neurotransmission, gliotransmission, and ultimately neuronal function at the cellular and system levels. Although a complete picture of intervening cellular mechanisms is lacking, some have been identified, notably certain permissive molecular factors common to systems capable of remodeling (cell surface and extracellular matrix adhesion molecules, cytoskeletal proteins) and molecules that appear specific to each system (neuropeptides, neurotransmitters, steroids, growth factors) that trigger or reverse the morphological changes.

Crisis and Human Biology

2015 ◽  
pp. 51-69 ◽  
Author(s):  
Prashant Bharadwaj ◽  
Tom Vogl
Keyword(s):  
Social Economic ◽  
Population Level ◽  
Crisis Response ◽  
Data Availability ◽  
Human Biology ◽  
Negative Events ◽  
Poor Countries ◽  
Beneficial Effects ◽  
Environmental Disasters ◽  
Biological Outcomes

This chapter reviews the literature on the effects of aggregate crises on human biological outcomes. The crises considered are acute, severe, and unexpected negative events occurring at the population level: recessions, famines, epidemics, natural and environmental disasters, and wars. A review of the literature suggests that the effects of aggregate crises on human biology are pervasive and long-lasting. More broadly, however, the literature highlights the lasting effects that social, economic, political, environmental, and pathological crises have on the human body. Children, who are never complicit in creating crises, carry the burden of exposure for the rest of their lives. Although advances in methodology and data availability have allowed researchers to uncover these nuanced but powerful effects, much work remains in improving crisis response, especially in poor countries. Such improvements would have beneficial effects long after the acute period of a crisis subsides, on outcomes far beyond its most obvious sequelae.

scholarly journals Quercetin Potentiates Docosahexaenoic Acid to Suppress Lipopolysaccharide-induced Oxidative/Inflammatory Responses, Alter Lipid Peroxidation Products, and Enhance the Adaptive Stress Pathways in BV-2 Microglial Cells

2019 ◽  
Vol 20 (4) ◽  
pp. 932 ◽  
Author(s):  
Grace Sun ◽  
Runting Li ◽  
Bo Yang ◽  
Kevin Fritsche ◽  
David Beversdorf ◽  
...  
Keyword(s):  
Docosahexaenoic Acid ◽  
Inflammatory Responses ◽  
Microglial Cells ◽  
Mammalian Brain ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Protective Effects ◽  
Beneficial Effects ◽  
Brain Functions ◽  
Study Results

High levels of docosahexaenoic acid (DHA) in the phospholipids of mammalian brain have generated increasing interest in the search for its role in regulating brain functions. Recent studies have provided evidence for enhanced protective effects when DHA is administered in combination with phytochemicals, such as quercetin. DHA and quercetin can individually suppress lipopolysaccharide (LPS)–induced oxidative/inflammatory responses and enhance the antioxidative stress pathway involving nuclear factor erythroid-2 related factor 2 (Nrf2). However, studies with BV-2 microglial cells indicated rather high concentrations of DHA (IC50 in the range of 60–80 µM) were needed to produce protective effects. To determine whether quercetin combined with DHA can lower the levels of DHA needed to produce protective effects in these cells is the goal for this study. Results showed that low concentrations of quercetin (2.5 µM), in combination with DHA (10 µM), could more effectively enhance the expression of Nrf2 and heme oxygenase 1 (HO-1), and suppress LPS–induced nitric oxide, tumor necrosis factor-α, phospho-cytosolic phospholipase A2, reactive oxygen species, and 4-hydroxynonenal, as compared to the same levels of DHA or quercetin alone. These results provide evidence for the beneficial effects of quercetin in combination with DHA, and further suggest their potential as nutraceuticals for improving health.

The Functional Consequences of Cortical Plasticity in Adult Humans

1998 ◽  
Vol 95 (s39) ◽  
pp. 17P-17P
Author(s):  
Ceg Moore ◽  
W Schady
Keyword(s):  
Cortical Plasticity ◽  
Adult Humans ◽  
Functional Consequences

scholarly journals Exploring the Engaged Worker over Time—A Week-Level Study of How Positive and Negative Work Events Affect Work Engagement

2021 ◽  
Vol 18 (13) ◽  
pp. 6699
Author(s):  
Oliver Weigelt ◽  
Antje Schmitt ◽  
Christine J. Syrek ◽  
Sandra Ohly
Keyword(s):  
Work Engagement ◽  
High Frequency ◽  
Negative Events ◽  
Organizational Life ◽  
Positive Events ◽  
Beneficial Effects ◽  
Current Events ◽  
Work Events ◽  
Job Demands And Resources ◽  
Over Time

Although work events can be regarded as pivotal elements of organizational life, only a few studies have examined how positive and negative events relate to and combine to affect work engagement over time. Theory suggests that, to better understand how current events affect work engagement (WE), we have to account for recent events that have preceded these current events. We present competing theoretical views on how recent and current work events may affect employees (e.g., getting used to a high frequency of negative events or becoming more sensitive to negative events). Although the occurrence of events implies discrete changes in the experience of work, prior research has not considered whether work events actually accumulate to sustained mid-term changes in WE. To address these gaps in the literature, we conducted a week-level longitudinal study across a period of 15 consecutive weeks among 135 employees, which yielded 849 weekly observations. While positive events were associated with higher levels of WE within the same week, negative events were not. Our results support neither satiation nor sensitization processes. However, a high frequency of negative events in the preceding week amplified the beneficial effects of positive events on WE in the current week. Growth curve analyses show that the benefits of positive events accumulate to sustain high levels of WE. WE dissipates in the absence of a continuous experience of positive events. Our study adds a temporal component by highlighting that positive events affect work engagement, particularly in light of recent negative events. Our study informs research that has taken a feature-oriented perspective on the dynamic interplay of job demands and resources.

scholarly journals Oxidative-Signaling in Neural Stem Cell-Mediated Plasticity: Implications for Neurodegenerative Diseases

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1088
Author(s):  
Mafalda Ferreira dos Santos ◽  
Catarina Roxo ◽  
Susana Solá
Keyword(s):  
Neurodegenerative Diseases ◽  
Mitochondrial Dysfunction ◽  
Current Knowledge ◽  
Bioactive Molecules ◽  
Mammalian Brain ◽  
Beneficial Effects ◽  
Mature Brain ◽  
Injured Brain ◽  
Therapeutic Properties ◽  
Adult Mammalian Brain

The adult mammalian brain is capable of generating new neurons from existing neural stem cells (NSCs) in a process called adult neurogenesis. This process, which is critical for sustaining cognition and mental health in the mature brain, can be severely hampered with ageing and different neurological disorders. Recently, it is believed that the beneficial effects of NSCs in the injured brain relies not only on their potential to differentiate and integrate into the preexisting network, but also on their secreted molecules. In fact, further insight into adult NSC function is being gained, pointing to these cells as powerful endogenous “factories” that produce and secrete a large range of bioactive molecules with therapeutic properties. Beyond anti-inflammatory, neurogenic and neurotrophic effects, NSC-derived secretome has antioxidant proprieties that prevent mitochondrial dysfunction and rescue recipient cells from oxidative damage. This is particularly important in neurodegenerative contexts, where oxidative stress and mitochondrial dysfunction play a significant role. In this review, we discuss the current knowledge and the therapeutic opportunities of NSC secretome for neurodegenerative diseases with a particular focus on mitochondria and its oxidative state.

scholarly journals BDNF produced by cerebral microglia promotes cortical plasticity and pain hypersensitivity after peripheral nerve injury

PLoS Biology ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. e3001337
Author(s):  
Lianyan Huang ◽  
Jianhua Jin ◽  
Kai Chen ◽  
Sikun You ◽  
Hongyang Zhang ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Cortical Plasticity ◽  
Conditional Knockout ◽  
Normal Density ◽  
Pain Hypersensitivity ◽  
Functional Changes ◽  
Beneficial Effects

Peripheral nerve injury–induced mechanical allodynia is often accompanied by abnormalities in the higher cortical regions, yet the mechanisms underlying such maladaptive cortical plasticity remain unclear. Here, we show that in male mice, structural and functional changes in the primary somatosensory cortex (S1) caused by peripheral nerve injury require neuron-microglial signaling within the local circuit. Following peripheral nerve injury, microglia in the S1 maintain ramified morphology and normal density but up-regulate the mRNA expression of brain-derived neurotrophic factor (BDNF). Using in vivo two-photon imaging and Cx3cr1CreER;Bdnfflox mice, we show that conditional knockout of BDNF from microglia prevents nerve injury–induced synaptic remodeling and pyramidal neuron hyperactivity in the S1, as well as pain hypersensitivity in mice. Importantly, S1-targeted removal of microglial BDNF largely recapitulates the beneficial effects of systemic BDNF depletion on cortical plasticity and allodynia. Together, these findings reveal a pivotal role of cerebral microglial BDNF in somatosensory cortical plasticity and pain hypersensitivity.

scholarly journals Mesenchymal Stem Cells: An Overview of Their Potential in Cell-Based Therapy for Diabetic Nephropathy

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yan Wu ◽  
Chunlei Zhang ◽  
Ran Guo ◽  
Dan Wu ◽  
Jiayi Shi ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Drug Targets ◽  
Renal Diseases ◽  
Beneficial Effects ◽  
Tissue Repair And Regeneration ◽  
Cell Based Therapy ◽  
Promising Strategy ◽  
Potential Benefits ◽  
Recent Phase ◽  
End Stage

Diabetic nephropathy (DN) is a devastating complication associated with diabetes mellitus, and it is the leading cause of end-stage renal diseases (ESRD). Over the last few decades, numerous studies have reported the beneficial effects of stem cell administration, specifically mesenchymal stem or stromal cells (MSCs), on tissue repair and regeneration. MSC therapy has been considered a promising strategy for ameliorating the progression of DN largely based on results obtained from several preclinical studies and recent Phase I/II clinical trials. This paper will review the recent literature on MSC treatment in DN. In addition, the roles and potential mechanisms involved in MSC treatment of DN will be summarized, which may present much needed new drug targets for this disease. Moreover, the potential benefits and related risks associated with the therapeutic action of MSCs are elucidated and may help in achieving a better understanding of MSCs.

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