1,720,971 research outputs found
Potential role for ligand-gated ion channels after seizure-induced neurogenesis
No full textEpileptic seizures result in an increased generation of new neurons in the dentate gyrus of the adult mammalian hippocampus. The role of these seizure-induced newborn neurons in the process of epileptogenesis remains largely unknown. Recent work, however, suggests an aberrant incorporation of newborn cells into the existing hippocampal network in such a way that they promote hippocampal hyperexcitability. in the present review, we discuss current knowledge about the possible role of seizure-induced newly generated neurons and the putative involvement of ligand-gated ion channels in the process of epileptogenesis.We are supported by the transnational University Limburg (tUL), the Research Foundation Flanders (FWO Vlaanderen) and the Interuniversity Attraction Poles Programme (IUAP - Belgian State - Belgian Science Policy). Hasselt University and University medical Center Maastricht are both member of Euron, the European Graduate School of Neuroscience
EFFECT OF EXPERIMENTAL FEBRILE SEIZURES ON DENDRITOGENESIS OF NEWBORN HIPPOCAMPAL DENTATE GRANULE CELLS
No full textEFFECT OF EXPERIMENTAL FEBRILE SEIZURES ON DENDRITOGENESIS OF NEWBORN HIPPOCAMPAL DENTATE GRANULE CELLS
No full textInteracties van cadmium met het ionentransport in de nier
No full textChronische blootstelling aan cadmium door inname van gecontamineerd voedsel en water of
door inhalatie van cadmiumbevattend stof leidt uiteindelijk tot accumulatie van dit nietessentiële
zware metaal in de nier. Cadmium induceert nefropathie, die gepaard gaat met een
verstoorde reabsorptie en secretie ter hoogte van de renale tubuli. Tubulaire schade
manifesteert zich via glucosurie, aminoacidurie, fosfaturie, hypercalciurie en proteïnurie,
vergelijkbaar met het Toni-Debré-Fanconi syndroom. De mechanismen van
cadmiumtoxiciteit in de renale tubulaire epitheelcellen zijn nog niet volledig opgehelderd.
Verscheidene studies suggereren het optreden van directe interacties tussen cadmium en
renale ionentransportsystemen.
Dit stageproject beoogt de analyse van de directe invloed van cadmium op specifieke
ionentransportsystemen in de apicale membraan van de distale en de proximale tubuli. In een
eerste luik van het project wordt het epitheliaal Na+ kanaal van de rat (rENaC) tot expressie
gebracht in Xenopus laevis oöcyten. De functionaliteit en activiteit van rENaC wordt
geëvalueerd met behulp van de ‘two micro-electrode voltage clamp’ (TEVC) techniek. De
invloed van cadmium op rENaC wordt getest door toevoeging van CdCl2 aan de
extracellulaire oplossing in verschillende eindconcentraties. In een tweede deel van het
project wordt er beoogd het volledig mRNA van de renale Na+/glucose cotransporter
(SGLT2) van de muis te bekomen. Totaal RNA, geïsoleerd uit de corticale delen van
muizennieren, fungeert als uitgangsmateriaal voor de cDNA synthese. Vervolgens wordt er
met behulp van PCR en SGLT2-specifieke primers geprobeerd het volledige SGLT2 cDNA te
amplificeren.
Elektrofysiologische metingen aan oöcyten die rENaC tot expressie brengen, tonen aan dat
het kanaal gereguleerd wordt door zowel intracellulair natrium als extracellulair cadmium.
Nochtans hebben lage CdCl2 concentraties (0.010, 0.100 en 1 mM) geen invloed op rENaC,
maar wordt een verhoogde activiteit van rENaC slechts geregistreerd vanaf een CdCl2
concentratie van 2.5 mM. Toxicologische effecten van cadmium ter hoogte van ENaC zijn
bijgevolg van ondergeschikt belang. Cadmium kan wel dienen om de structurele
eigenschappen van ENaC te analyseren
Experimental early‐life febrile seizures cause a sustained increase in excitatory neurotransmission in newborn dentate granule cells
No full textProlonged febrile seizures (FS) are a risk factor for the development of hippocampal-associated temporal lobe epilepsy. The dentate gyrus is the major gateway to the hippocampal network and one of the sites in the brain where neurogenesis continues postnatally. Previously, we found that experimental FS increase the survival rate and structural integration of newborn dentate granule cells (DGCs). In addition, mature post-FS born DGCs express an altered receptor panel. Here, we aimed to study if these molecular and structural changes are accompanied by an altered cellular functioning. Experimental FS were induced by hyperthermia in 10-days-old Sprague-Dawley rats. Proliferating progenitor cells were labeled the next day by injecting green fluorescent protein expressing retroviral particles bilaterally in the dentate gyri. Eight weeks later, spontaneous excitatory and inhibitory postsynaptic events (sEPSCs and sIPSCs, respectively) were recorded from labeled DGCs using the whole-cell patch-clamp technique. Experimental FS resulted in a robust decrease of the inter event interval (p < .0001) and a small decrease of the amplitude of sEPSCs (p < .001). Collectively the spontaneous excitatory charge transfer increased (p < .01). Experimental FS also slightly increased the frequency of sIPSCs (p < .05), while the amplitude of these events decreased strongly (p < .0001). The net inhibitory charge transfer remained unchanged. Experimental, early-life FS have a long-term effect on post-FS born DGCs, as they display an increased spontaneous excitatory input when matured. It remains to be established if this presents a mechanism for FS-induced epileptogenesis.Funding information: ‘Bijzonder Onderzoeksfonds’ grant from Hasselt Universit
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The role of ligand-gated ion channels after early-life febrile seizures
No full textIn this thesis, we aimed at elucidating some mechanisms by which early-life FS may lead to enhanced hippocampal excitability. We focused on the DG structure and investigated if FS-induced expressional and functional alterations of ligandgated ion channels (LGICs) in the DG may contribute to a disturbed DG ‘gate’ function. To this end, we used an appropriate-aged animal model in which FS are evoked in 10-day old rat pups by exposing them to heated air. In this model, FS are associated with long-term hippocampal hyperexcitability resulting in a decreased seizure threshold. 35% of rats with early-life FS develop TLE in adulthood, while 88% show interictal epileptoform EEG abnormalities. ..
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
The role of ligand-gated ion channels after early-life febrile seizures
No full textIn this thesis, we aimed at elucidating some mechanisms by which early-life FS may lead to enhanced hippocampal excitability. We focused on the DG structure and investigated if FS-induced expressional and functional alterations of ligandgated ion channels (LGICs) in the DG may contribute to a disturbed DG ‘gate’ function. To this end, we used an appropriate-aged animal model in which FS are evoked in 10-day old rat pups by exposing them to heated air. In this model, FS are associated with long-term hippocampal hyperexcitability resulting in a decreased seizure threshold. 35% of rats with early-life FS develop TLE in adulthood, while 88% show interictal epileptoform EEG abnormalities. ..
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