26 research outputs found

    Neuroadaptations in the Cellular and Postsynaptic Group 1 Metabotropic Glutamate Receptor mGluR5 and Homer Proteins Following Extinction of Cocaine Self-administration

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    This study examined the role of group1 metabotropic glutamate receptor mGluR5 and associated postsynaptic scaffolding protein Homer1b/c in behavioral plasticity after three withdrawal treatments from cocaine self-administration. Rats self-administered cocaine or saline for 14 days followed by a withdrawal period during which rats underwent extinction training, remained in their home cages, orwere placed in the self-administration chambers in the absence of extinction. Subsequently, the tissue level and distribution of proteins in the synaptosomal fraction associated with the postsynaptic densitywere examined. Cocaine self-administration followed by home cage exposure reduced the mGluR5 protein in nucleus accumbens (NA) shell and dorsolateral striatum. While extinction training reduced mGluR5 protein in NAshell, NAcore and dorsolateral striatum did not display any change. The scaffolding protein PSD95 increased in NAcore of the extinguished animals. Extinction of drug seeking was associated with a significant decrease in the synaptosomal mGluR5 protein in NAshell and an increase in dorsolateral striatum, while that of NAcore was not modified. Interestingly, both Homer1b/c and PSD95 scaffolding proteins were decreased in the synaptosomal fraction after extinction training in NAshell but not NAcore. Extinguished drug-seeking behavior was also associated with an increase in the synaptosomal actin proteins in dorsolateral striatum. Therefore, extinction of cocaine seeking is associated with neuroadaptations in mGluR5 expression and distribution that are region-specific and consist of extinction-induced reversal of cocaine-induced adaptations aswell as emergent extinction-induced alterations. Concurrent plasticity in the scaffolding proteins further suggests that mGluR5 receptor neuroadaptations may have implications for synaptic function

    Glutamatergic Plasticity in Medial Prefrontal Cortex and Ventral Tegmental Area Following Extended-Access Cocaine Self-Administration

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    Glutamate signaling in prefrontal cortex and ventral tegmental area plays an important role in the molecular and behavioral plasticity associated with addiction to drugs of abuse. The current study investigated the expression and postsynaptic density redistribution of glutamate receptors and synaptic scaffolding proteins in dorsomedial and ventromedial prefrontal cortex and ventral tegmental area after cocaine self-administration. After 14 days of extended-access (6 h/day) cocaine self-administration, rats were exposed to one of three withdrawal regimen for 10 days. Animals either stayed in home cages (Home), returned to self-administration boxes with the levers withdrawn (Box), or underwent extinction training (Extinction). Extinction training was associated with significant glutamatergic plasticity. In dorsomedial prefrontal cortex of the Extinction group, there was an increase in postsynaptic density GluR1, PSD95, and actin proteins; while postsynaptic density mGluR5 protein decreased and there was no change in NMDAR1, Homer1b/c, or PICK1 proteins. These changes were not observed in ventromedial prefrontal cortex or ventral tegmental area. In ventral tegmental area, Extinction training reversed the decreased postsynaptic density NMDAR1 protein in the Home and Box withdrawal groups. These data suggest that extinction of drug seeking is associated with selective glutamatergic plasticity in prefrontal cortex and ventral tegmental area that include modulation of receptor trafficking to postsynaptic density

    An Improved Under-Frequency Load Shedding Scheme in Distribution Networks with Distributed Generation

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    When a distribution network consisting of Distributed Generations (DGs) is disconnected from upstream network, the system may be exposed to severe power imbalance. In order to prevent the damage of power plants, frequency relays operate and remove DGs from the network. In contrast to traditional methods, the main objective in new methods is to keep DG units in service in the islanded distribution system. Under-Frequency Load Shedding (UFLS) is one of the most important protection systems, which is the last chance for avoiding a system blackout following severe disturbance. This paper dealt with an adaptive UFLS method and considered the priority of loads to be shed, depending on the intensity of event, and loads look up table built by Rate of Change of Frequency of Loads (ROCOFL) indices based on the frequency of centre of inertia (fCOI). Different loads were shed depending on the event type diagnosed by measuring the initial Rate of Change of Frequency (ROCOF) in the method. The proposed UFLS method can stabilize the frequency of the distribution system in islanding mode by shedding sufficient loads. The simulation results confirmed the advantages of the methods in comparison to other proposed algorithms

    Enhancing Cell Seeding and Osteogenesis of MSCs on 3D Printed Scaffolds Through Injectable BMP2 Immobilized ECM-Mimetic Gel

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    Objective Design of bioactive scaffolds with osteogenic capacity is a central challenge in cell-based patient-specific bone tissue engineering. Efficient and spatially uniform seeding of (stem) cells onto such constructs is vital to attain functional tissues. Herein we developed heparin functionalized collagen gels supported by 3D printed bioceramic scaffolds, as bone extracellular matrix (ECM)-mimetic matrices. These matrices were designed to enhance cell seeding efficiency of mesenchymal stem cells (MSCs) as well as improve their osteogenic differentiation through immobilized bone morphogenic protein 2 (BMP2) to be used for personalized bone regeneration. Methods A 3D gel based on heparin-conjugated collagen matrix capable of immobilizing recombinant human bone morphogenic protein 2 (BMP2) was synthesized. Isolated dental pulp Mesenchymal stem cells (MSCs) were then encapsulated into the bone ECM microenvironment to efficiently and uniformly seed a bioactive ceramic-based scaffold fabricated using additive manufacturing technique. The designed 3D cell-laden constructs were comprehensively investigated trough in vitro assays and in vivo study. Results In-depth rheological characterizations of heparin-conjugated collagen gel revealed that elasticity of the matrix is significantly improved compared with freely incorporated heparin. Investigation of the MSCs laden collagen-heparin hydrogels revealed their capability to provide spatiotemporal bioavailability of BMP2 while suppressing the matrix contraction over time. The in vivo histology and real-time polymerase chain reaction (qPCR) analysis showed that the designed construct supported the osteogenic differentiation of MSCs and induced the ectopic bone formation in rat model. Significance The presented hybrid constructs combine bone ECM chemical cues with mechanical function providing an ideal 3D microenvironment for patient-specific bone tissue engineering and cell therapy applications. The implemented methodology in design of ECM-mimetic 3D matrix capable of immobilizing BMP2 to improve seeding efficiency of customized scaffolds can be exploited for other bioactive molecules

    Modeling and Analysis of Barriers to Climate Change Adaptation in Tehran

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    Since the impacts of climate change will last for many years, adaptation to this phenomenon should be prioritized in urban management plans. Although Tehran, the capital of Iran, has been subject to a variety of climate change impacts in recent years, appropriate adaptation measures to address them are yet to be taken. This study primarily aims to categorize the barriers to climate change adaptation in Tehran and analyze the way they interact with each other. The study was done in three steps: first, the focus group discussion (FGD) method was used to identify the barriers; next, the survey and the structural equation modeling (SEM) were used to validate the barriers, identify their importance, and examine their possible inter-relationships; and finally, the interpretive structural modeling (ISM) was applied to categorize and visualize the relationships between the barriers. Results show that barriers related to the ‘structure and culture of research’, ‘laws and regulations’, and ‘planning’ belong to the cluster of independent barriers and are of greater significance. The ‘social’ barrier and barriers related to ‘resources and resource management’ are identified as dependent barriers and are of lesser importance. Barriers related to ‘governance’, ‘awareness’, ‘education and knowledge’, ‘communication and interaction’, and ‘economy’ are identified at the intermediate cluster. The findings of this study can provide planners and decision makers with invaluable insights as to how to develop strategies for climate change adaptation in Tehran. Despite the scope of the study being confined to Tehran, its implications go far beyond this metropolis

    Framework – architecture in iranian miniatures

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    CROSS-TRADITIONAL BOUNDARIES OF URBAN PLANNING

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    This research explores the cross-traditional boundaries of urban planning and design. Using the United States as an example, many urban areas have become epicenters for crime, squalor and destitution. However, many cities have reinvigorated and revitalized urban areas to make them colorful, vibrant and product to society rather than being a focal point of crime and urban blight. This is where an effective urban planner comes into play. A good urban planner and/or designer will know the principles to adhere to and steps to take to maintain or improve the conditions of an urban area through effective planning and design. There are different major parts to this subject but they blend and mold together in many different ways. The objective of this research is to identify the trends and patterns that define good urban design and planning and some examples that are not emblematic of good practice. The methodology behind this study will be mostly qualitative analysis. The scope of what will be looked at will be urban areas within the United States. The findings of this report is that urban planning design is sometimes done extremely well and with excellent results while other times it is done quite poorly despite a wealth of funding and resources to help do it right the first time. The overall conclusion of this study is that urban planning can be done extremely well but the methodology and specifics to the urban area in question matter greatly

    The role of cultural gathering spaces in the promotion of citizen quality of life case study: Tehran City Theater

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    A city as a context of urban human life requires meeting some standards which at a glance are called the standards of life quality. In fact, the quality of life is a complex and multi-dimensional concept. Measuring the quality of life in Iran, according to particular social, economic and cultural conditions of this country and also the emphasis of country twenty years visions on this issue, has special importance. Cultural gathering spaces improve social and economic vitality in one side and in other side provide favorable conditions for citizen leisure. Theatres are one of cultural complexes which have important role in the promotion of citizens' quality of life. What is today known as Tehran City Theatre is a beautiful circular cylindrical building which is located at Daneshjoo park ,Vali-e-Asr crossroad ,Tehran city; and for some reasons daily attracts hundreds of people. The objective of this study is to explain the role of City Theatre in promoting citizens' quality of life. Research method is analytical descriptive. Data collection method has been based on researcher's objective assessments and filling questionnaire. Cochran's formula was used to determine sampling volume and questionnaires were distributed among citizens of district 11, Tehran city; then 480 questionnaires gathered and analyzed. The research findings show that City Theatre has an effective and positive role on mental dimension of citizens' quality of life. The capabilities of this collection can be increased for citizens' quality of life by creating facilities such as transportation control and avoiding interference of riding and pedestrian, creating sitting and pause spaces in this collection, and spaces associated with this collection using
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