Differential localization of GABAA receptor subunits in relation to rat striatopallidal and pallidopallidal synapses

As a central integrator of basal ganglia function, the external segment of the globus pallidus (GP) plays a critical role in the control of voluntary movement. The GP is composed of a network of inhibitory GABA-containing projection neurons which receive GABAergic input from axons of the striatum (Str) and local collaterals of GP neurons. Here, using electrophysiological techniques and immunofluorescent labeling we have investigated the differential cellular distribution of a1, a2 and a3 GABAA receptor subunits in relation to striatopallidal (Str-GP) and pallidopallidal (GP-GP) synapses. Electrophysiological investigations showed that zolpidem (100 nm; selective for the a1 subunit) increased the amplitude and the decay time of both Str-GP and GP-GP IPSCs, indicating the presence of the a1 subunits at both synapses. However, the application of drugs selective for the a2, a3 and a5 subunits (zolpidem at 400 nm, L-838,417 and TP003) revealed differential effects on amplitude and decay time of IPSCs, suggesting the nonuniform distribution of non-a1 subunits. Immunofluorescence revealed widespread distribution of the a1 subunit at both soma and dendrites, while double- and triple-immunofluorescent labeling for parvalbumin, enkephalin, gephyrin and the ?2 subunit indicated strong immunoreactivity for GABAAa3 subunits in perisomatic synapses, a region mainly targeted by local axon collaterals. In contrast, immunoreactivity for synaptic GABAAa2 subunits was observed in dendritic compartments where striatal synapses are preferentially located. Due to the kinetic properties which each GABAAa subunit confers, this distribution is likely to contribute differentially to both physiological and pathological patterns of activity.

Metadata and Geospatial Data Processing on the Base of XML and Grid

The software architecture and development consideration for open metadata extraction and processing framework are outlined. Special attention is paid to the aspects of reliability and fault tolerance. Grid infrastructure is shown as useful backend for general-purpose task.

Grid-enabling Satellite Image Archive Prototype for UA Space Grid Testbed

* The work is partially supported by the grant of National Academy of Science of Ukraine for the support of scientific researches by young scientists No 24-7/05, " Розробка Desktop Grid-системи і оптимізація її продуктивності ”.

Functional neuroanatomy and behavioural correlates of the basal ganglia:evidence from lesion studies

Introduction: The basal ganglia are interconnected with cortical areas involved in behavioural, cognitive and emotional processes, in addition to movement regulation. Little is known about which of these functions are associated with individual basal ganglia substructures. Methods: Pubmed was searched for literature related to behavioural, cognitive and emotional symptoms associated with focal lesions to basal ganglia structures in humans. Results: Six case-control studies and two case reports were identified as relevant. Lesion sites included the caudate nucleus, putamen and globus pallidus. These were associated with a spectrum of behavioural and cognitive symptoms, including abulia, poor working memory and deficits in emotional recognition. Discussion: It is often difficult to precisely map associations between cognitive, emotional or behavioural functions and particular basal ganglia substructures, due to the non-specific nature of the lesions. However, evidence from lesion studies shows that most symptoms correspond with established non-motor frontal-subcortical circuits. © 2013-IOS Press and the authors. All rights reserved.

Simulazione della bradicinesia in soggetti parkinsoniani attraverso modello neurale

I Gangli della Base svolgono un ruolo molto importante nel movimento volontario, ovvero nel meccanismo di azione-selezione, e la loro influenza è evidente soprattutto in alcune patologie che ancora ad oggi sono in fase di studio: una di queste è il Morbo di Parkinson. I Gangli della Base comprendono quattro formazioni nervose: lo striato, il globus pallidus, la substantia nigra e il nucleo subtalamico: essi ricevono le principali afferenze dalla corteccia cerebrale ed inviano le principali efferenze al tronco dell’encefalo, e, per mezzo del talamo, alle corteccia prefrontale, premotoria e motrice. A differenza della maggior parte delle altre componenti dei sistemi motori, i Gangli della Base non stabiliscono direttamente né connessioni afferenti, né efferenti con il midollo spinale. Il compito principale svolto dai Gangli dDella Base è la selezione di un’azione: esso permette ad un’azione di essere selezionata rispetto ad un’altra, che in questo modo viene inibita. La descrizione dell’anatomia, dei meccanismi fisiologici e del Morbo di Parkinson è trattata nel Capitolo 1. In questo elaborato è utilizzato il modello computazionale di Mauro Ursino e Chiara Baston, che sarà illustrato dettagliatamente nel Capitolo 2, riguardante il meccanismo di azione-selezione svolto dai Gangli della Base. E’ descritto un sistema di valutazione di un paziente parkinsoniano, il tapping test: esso consiste in un movimento alternato del dito e ad oggi risulta essere uno dei metodi più semplici per ottenere informazioni sulla gravità della bradicinesia. L’obiettivo di questo lavoro è quello di comprendere, tramite l’analisi di simulazioni effettuate per mezzo del modello computazionale di Mauro Ursino e Chiara Baston, come la frequenza di tapping dipenda dal variare di alcuni parametri delle equazioni del modello: gli effetti dovuti alla variazione di un singolo parametro o più di uno, saranno mostrati nel Capitolo 3.

Organisation chimioanatomique des afférences pallidales chez le primate

L’élucidation de la position qu’occupent les projections sérotoninergique (5-HT), cholinergique (ACh) et dopaminergique (DA) du tronc cérébral dans l’organisation anatomofonctionelle du globus pallidus externe (GPe) et interne (GPi) au sein des ganglions de la base chez le primate est primordiale à la compréhension de ce système neuronal hautement complexe impliqué dans le contrôle du comportement moteur. Les travaux de recherche consolidés dans la présente thèse rapportent les résultats principalement obtenus chez le singe écureuil (Saimiri sciureus) à l’aide de marquages immunohistochimiques et de quantifications stéréologiques servant à évaluer la distribution régionale et les caractéristiques ultrastructurales des varicosités axonales 5-HT, ACh et DA observées dans le pallidum. Nos données ont permis l’éloboration d’un nouveau modèle du neurone pallidal en tenant compte de la hiérarchie et des caractéristiques neurochimiques de ses entrées synaptiques. Ainsi, l’analyse quantitative en microscopie optique révèle que le GPe et le GPi reçoivent des innervations 5-HT, ACh et DA de densités variables et distribuées de façon hétérogène. Plus particulièrement, le GPe est innervé par 600 000 varicosités 5-HT/mm3 de tissu, 500 000 varicosités ACh/mm3 et 170 000 varicosités DA/mm3. En revanche, le GPi reçoit 600 000 varicosités 5-HT/mm3, 250 000 varicosités ACh/mm3 et 190 000 varicosités DA/mm3. De plus, la 5-HT, l’ACh et la DA ciblent préférentiellement les secteurs correspondant aux territoires fonctionnels associatifs et limbiques du pallidum, suggérant un rôle de ces projections dans la planification du comportement moteur ainsi que dans la régulation de l’attention et de l’humeur. Nos analyses en microscopie électronique révèlent que très peu de ces varicosités axonales établissent un contact synaptique, puisque plus de 70% des varicosités 5-HT, ACh et DA sont complètement dépouvues de jonction synaptique. Ainsi, bien que la 5-HT, l’ACh et la DA seraient en mesure de moduler directement les neurones pallidaux grâce à la transmission synaptique, leur plus grande influence s’opérerait par la transmission volumique, permettant d’influencer à la fois les neurones pallidaux et leurs afférences, principalement du striatum et noyau subthalamique. L’ensemble de ces résultats indique que les projections 5-HT, ACh et DA du tronc cérébral agissent de concert avec les afférences plus robustes en provenance du striatum et du noyau subthalamique. Ces nouvelles données neuroanatomiques positionnent le tronc cérébral en tant qu’acteur important dans l’organisation anatomique et fonctionnelle du pallidum chez le primate et doivent être prises en considération dans l’élaboration de nouvelles approches thérapeutiques visant à contrer les processus neurodégénératifs qui affectent les ganglions de la base, tel que la maladie de Parkinson.

A study on the deployment of GA in a grid computing framework

Dissertação de Mestrado, Engenharia Informática, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

Urban air quality: new high-resolution modeling approaches and forecasting tools for citizens

Air pollution is one of the greatest health risks in the world. At the same time, the strong correlation with climate change, as well as with Urban Heat Island and Heat Waves, make more intense the effects of all these phenomena. A good air quality and high levels of thermal comfort are the big goals to be reached in urban areas in coming years. Air quality forecast help decision makers to improve air quality and public health strategies, mitigating the occurrence of acute air pollution episodes. Air quality forecasting approaches combine an ensemble of models to provide forecasts from global to regional air pollution and downscaling for selected countries and regions. The development of models dedicated to urban air quality issues requires a good set of data regarding the urban morphology and building material characteristics. Only few examples of air quality forecast system at urban scale exist in the literature and often they are limited to selected cities. This thesis develops by setting up a methodology for the development of a forecasting tool. The forecasting tool can be adapted to all cities and uses a new parametrization for vegetated areas. The parametrization method, based on aerodynamic parameters, produce the urban spatially varying roughness. At the core of the forecasting tool there is a dispersion model (urban scale) used in forecasting mode, and the meteorological and background concentration forecasts provided by two regional numerical weather forecasting models. The tool produces the 1-day spatial forecast of NO2, PM10, O3 concentration, the air temperature, the air humidity and BLQ-Air index values. The tool is automatized to run every day, the maps produced are displayed on the e-Globus platform, updated every day. The results obtained indicate that the forecasting output were in good agreement with the observed measurements.