scholarly journals Percolation in networks with local homeostatic plasticity

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Giacomo Rapisardi ◽  
Ivan Kryven ◽  
Alex Arenas
Keyword(s):  
Biological Networks ◽  
Transportation Systems ◽  
Active Networks ◽  
Homeostatic Plasticity ◽  
Neural Cells ◽  
Epidemic Spreading ◽  
Synaptic Scaling ◽  
Critical Transitions ◽  
Network Connectedness

AbstractPercolation is a process that impairs network connectedness by deactivating links or nodes. This process features a phase transition that resembles paradigmatic critical transitions in epidemic spreading, biological networks, traffic and transportation systems. Some biological systems, such as networks of neural cells, actively respond to percolation-like damage, which enables these structures to maintain their function after degradation and aging. Here we study percolation in networks that actively respond to link damage by adopting a mechanism resembling synaptic scaling in neurons. We explain critical transitions in such active networks and show that these structures are more resilient to damage as they are able to maintain a stronger connectedness and ability to spread information. Moreover, we uncover the role of local rescaling strategies in biological networks and indicate a possibility of designing smart infrastructures with improved robustness to perturbations.

scholarly journals A Bidirectional Switch in the Shank3 Phosphorylation State Biases Synapses toward Up or Down Scaling

2021 ◽  
Author(s):  
Gina G Turrigiano ◽  
Chi-Hong Wu ◽  
Vedakumar Tatavarty ◽  
Pierre M Jean-Beltran ◽  
Andrea Guerrero ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Scaling Up ◽  
Homeostatic Plasticity ◽  
Synaptic Scaling ◽  
Synaptic Localization ◽  
Neocortical Neurons ◽  
Associated Proteins ◽  
Scaling Down ◽  
Activity Dependent

Homeostatic synaptic plasticity requires widespread remodeling of synaptic signaling and scaffolding networks, but the role of posttranslational modifications in this process has not been systematically studied. Using deepscale, quantitative analysis of the phosphoproteome in mouse neocortical neurons, we found wide-spread and temporally complex changes during synaptic scaling up and down. We observed 424 bidirectionally modulated phosphosites that were strongly enriched for synapse-associated proteins, including S1539 in the ASD-associated synaptic scaffold protein Shank3. Using a parallel proteomic analysis performed on Shank3 isolated from rat neocortical neurons by immunoaffinity, we identified two sites that were hypo-phosphorylated during scaling up and hyper-phosphorylated during scaling down: one (rat S1615) that corresponded to S1539 in mouse, and a second highly conserved site, rat S1586. The phosphorylation status of these sites modified the synaptic localization of Shank3 during scaling protocols, and dephosphorylation of these sites via PP2A activity was essential for the maintenance of synaptic scaling up. Finally, phosphomimetic mutations at these sites prevented scaling up but not down, while phosphodeficient mutations prevented scaling down but not up. Thus, an activity-dependent switch between hypo- and hyperphosphorylation at S1586/ S1615 of Shank3 enables scaling up or down, respectively. Collectively our data show that activity-dependent phosphoproteome dynamics are important for the functional reconfiguration of synaptic scaffolds, and can bias synapses toward upward or downward homeostatic plasticity.

scholarly journals Homeostatic Synaptic Scaling Establishes the Specificity of an Associative Memory

2020 ◽  
Author(s):  
Chi-Hong Wu ◽  
Raul Ramos ◽  
Donald B Katz ◽  
Gina G Turrigiano
Keyword(s):  
Associative Memory ◽  
Memory Formation ◽  
Homeostatic Plasticity ◽  
Synaptic Scaling ◽  
Memory Specificity ◽  
Hebbian Plasticity ◽  
Dependent Form ◽  
Subsequent Loss ◽  
Stable Memory

AbstractAccurate memory formation has been hypothesized to depend on both rapid Hebbian plasticity for initial encoding, and slower homeostatic mechanisms that prevent runaway excitation and subsequent loss of memory specificity. Here, we tested the role of synaptic scaling in shaping the specificity of conditioned taste aversion (CTA) memory, a Hebbian plasticity-dependent form of associative learning. We found that CTA memory initially generalized to non-conditioned tastants (generalized aversion), becoming specific to the conditioned tastant only over the course of many hours. Blocking synaptic scaling in the gustatory cortex (GC) prolonged the duration of the initial generalized aversion and enhanced the persistence of synaptic strength increases observed after CTA. Taken together, these findings demonstrate that synaptic scaling is important for sculpting the specificity of an associative memory and suggest that the relative strengths of Hebbian and homeostatic plasticity can modulate the balance between stable memory formation and generalization.

scholarly journals The Protective Role of Brain CYP2J in Parkinson’s Disease Models

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yueran Li ◽  
Jinhua Wu ◽  
Xuming Yu ◽  
Shufang Na ◽  
Ke Li ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Brain Regions ◽  
Protective Role ◽  
Neural Cells ◽  
Endogenous Substrates ◽  
6 Hydroxydopamine ◽  
Myd88 Signaling ◽  
Lps Treatment

CYP2J proteins are present in the neural cells of human and rodent brain regions. The aim of this study was to investigate the role of brain CYP2J in Parkinson’s disease. Rats received right unilateral injection with lipopolysaccharide (LPS) or 6-hydroxydopamine (6-OHDA) in the substantia nigra following transfection with or without the CYP2J3 expression vector. Compared with LPS-treated rats, CYP2J3 transfection significantly decreased apomorphine-induced rotation by 57.3% at day 12 and 47.0% at day 21 after LPS treatment; moreover, CYP2J3 transfection attenuated the accumulation of α-synuclein. Compared with the 6-OHDA group, the number of rotations by rats transfected with CYP2J3 decreased by 59.6% at day 12 and 43.5% at day 21 after 6-OHDA treatment. The loss of dopaminergic neurons and the inhibition of the antioxidative system induced by LPS or 6-OHDA were attenuated following CYP2J3 transfection. The TLR4-MyD88 signaling pathway was involved in the downregulation of brain CYP2J induced by LPS, and CYP2J transfection upregulated the expression of Nrf2 via the inhibition of miR-340 in U251 cells. The data suggest that increased levels of CYP2J in the brain can delay the pathological progression of PD initiated by inflammation or neurotoxins. The alteration of the metabolism of the endogenous substrates (e.g., AA) could affect the risk of neurodegenerative disease.

scholarly journals PPAR Gamma and Viral Infections of the Brain

2021 ◽  
Vol 22 (16) ◽  
pp. 8876
Author(s):  
Pierre Layrolle ◽  
Pierre Payoux ◽  
Stéphane Chavanas
Keyword(s):  
Viral Infections ◽  
Ppar Gamma ◽  
Brain Parenchyma ◽  
Peroxisome Proliferator ◽  
Neural Cells ◽  
Peroxisome Proliferator Activated Receptor ◽  
Immunodeficiency Virus ◽  
Health And Disease ◽  
The Brain

Peroxisome Proliferator-Activated Receptor gamma (PPARγ) is a master regulator of metabolism, adipogenesis, inflammation and cell cycle, and it has been extensively studied in the brain in relation to inflammation or neurodegeneration. Little is known however about its role in viral infections of the brain parenchyma, although they represent the most frequent cause of encephalitis and are a major threat for the developing brain. Specific to viral infections is the ability to subvert signaling pathways of the host cell to ensure virus replication and spreading, as deleterious as the consequences may be for the host. In this respect, the pleiotropic role of PPARγ makes it a critical target of infection. This review aims to provide an update on the role of PPARγ in viral infections of the brain. Recent studies have highlighted the involvement of PPARγ in brain or neural cells infected by immunodeficiency virus 1, Zika virus, or human cytomegalovirus. They have provided a better understanding on PPARγ functions in the infected brain, and revealed that it can be a double-edged sword with respect to inflammation, viral replication, or neuronogenesis. They unraveled new roles of PPARγ in health and disease and could possibly help designing new therapeutic strategies.

scholarly journals THE ROLE OF HISTORICAL SCIENCES ON THE DEVELOPMENT OF URBAN PUBLIC TRANSPORTATION IN 21st CENTURY INDONESIA

2021 ◽  
Author(s):  
Muhammad Luthfi Lazuardi ◽  
Moses Glorino Rumambo Pandin
Keyword(s):  
21St Century ◽  
Public Transport ◽  
Public Transportation ◽  
Transportation Systems ◽  
City Government ◽  
Historical Science ◽  
City Governments ◽  
Online Portal ◽  
The City

Public transportation is one of the most critical needs for a city, including in Indonesia. The fast and dynamic movement of society makes public transportation expected to accommodate the needs of city residents to move more quickly and efficiently. Available public transport can also reduce congestion because many city residents are switching from their private vehicles. Many cities in Indonesia are competing to develop their public transportation to modernize the life of the town. Problems will arise if the city government does not learn from history in planning the development of public transport in the city. This study aims to examine the role of historical science in the development of urban public transportation in Indonesia. The method used in this research is descriptive-qualitative through literature review by analyzing data and information according to the topic of the research topic. The data and information are sourced from 20 journal articles and five credible online portal sites with published years between 2019-2021. The result of this study is the role of historical science in the development of urban public transportation in Indonesia as a reference for city governments to reorganize their transportation systems in the future. This research has research limitations on the development of urban public transport in Indonesia in the 21st century. The researcher recommends further research on the role and benefits of historical science in improving urban public transportation in Indonesia to complement some lacking things from this research. At the same time was adding to the scientific treasures for many people, significant position holders in city government to be more intense in using historical knowledge as an essential study to encourage a better civilization of a city by improving the public transportation system.

scholarly journals Neurogenesis and Increase in Differentiated Neural Cell Survival via Phosphorylation of Akt1 after Fluoxetine Treatment of Stem Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Anahita Rahmani ◽  
Danial Kheradmand ◽  
Peyman Keyhanvar ◽  
Alireza Shoae-Hassani ◽  
Amir Darbandi-Azar
Keyword(s):  
Survival Rate ◽  
Cell Survival ◽  
Neural Cell ◽  
Neural Cells ◽  
Chain Reaction ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Fluoxetine Treatment ◽  
Polymerase Chain

Fluoxetine (FLX) is a selective serotonin reuptake inhibitor (SSRI). Its action is possibly through an increase in neural cell survival. The mechanism of improved survival rate of neurons by FLX may relate to the overexpression of some kinases such as Akt protein. Akt1 (a serine/threonine kinase) plays a key role in the modulation of cell proliferation and survival. Our study evaluated the effects of FLX on mesenchymal stem cell (MSC) fate and Akt1 phosphorylation levels in MSCs. Evaluation tests included reverse transcriptase polymerase chain reaction, western blot, and immunocytochemistry assays. Nestin, MAP-2, andβ-tubulin were detected after neurogenesis as neural markers. TenμM of FLX upregulated phosphorylation of Akt1 protein in induced hEnSC significantly. Also FLX did increase viability of these MSCs. Continuous FLX treatment after neurogenesis elevated the survival rate of differentiated neural cells probably by enhanced induction of Akt1 phosphorylation. This study addresses a novel role of FLX in neurogenesis and differentiated neural cell survival that may contribute to explaining the therapeutic action of fluoxetine in regenerative pharmacology.

The Role of a Sustainability Informatics Framework in Transportation Systems

2014 ◽  
Vol 6 (3) ◽  
pp. 43-59 ◽  
Author(s):  
Lin Jia ◽  
Barry Cumbie ◽  
Chetan S. Sankar ◽  
Jian Yu
Keyword(s):  
Information Technology ◽  
Information Systems ◽  
Triple Bottom Line ◽  
Nation Building ◽  
Transportation Systems ◽  
Bottom Line ◽  
Energy Informatics ◽  
Research Propositions ◽  
Sustainability Indices

This article develops a Sustainability Informatics Framework, a framework that connects Information Technology with sustainability and is based on the Belief-Action-Outcome and Energy Informatics frameworks. The triple-bottom line (People, Planet, and Profit) is adopted as a criterion for measuring sustainability and three sustainability indices are first formulated and then visualized using Sustainability Dashboards. This framework is then used to analyze transportation systems. This leads to the development of research propositions that can expand the role of the Information Systems discipline to research on areas of sustainable nation building.

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