Time-dependent changes in GLT-1 functioning in striatum of hemi-Parkinson rats

Striatal dopamine loss in Parkinson's disease is accompanied by a dysregulation of corticostriatal glutamatergic neurotransmission. Within this study, we investigated striatal expression and activity of the glial high-affinity Na+/K+-dependent glutamate transporters, GLT-1 and GLAST, in the 6-hydroxydopamine hemi-Parkinson rat model at different time points after unilateral 6-hydroxydopamine injection into the medial forebrain bundle. Using semi-quantitative Western blotting and an ex vivo D-[H-3]-aspartate uptake assay, we showed a time-dependent bilateral effect of unilateral 6-hydroxydopamine lesioning on the expression as well as activity of GLT-1. At 3 and 12 weeks post-lesion, striatal GLT-1 function was bilaterally upregulated whereas at 5 weeks there was no change. Even though our data do not allow a straightforward conclusion as for the role of glutamate transporters in the pathogenesis of the disease, they do clearly demonstrate a link between disturbed glutamatergic neurotransmission and glutamate transporter functioning in the striatum of a rat model for Parkinson's disease. (C) 2010 Elsevier Ltd. All rights reserved

Composer avec le monde

À l’heure où le numérique fait émerger de nouveaux modes d’écriture, d’écoute, d’échange, de circulation et de stockage des données, mais aussi de nouvelles formes d’autorité, d’économies et de types de relation au temps et au monde, ce numéro interroge les notions de création musicale et chorégraphique en contexte de globalisation. À travers une série d’études de cas qui dépassent les distinctions Nord/Sud, écrit/oral, savant/populaire, religieux/profane, on saisit mieux comment ces pratiques participent d’un même régime de création qui, tantôt intègre, tantôt met en tension deux logiques, l’une du renouvellement, l’autre de l’innovation. De la même manière, ces pratiques de composition et de recomposition sont interrogées en termes de régimes d’autorité, ce qui permet de montrer que, dans de multiples régions du monde, des solutions alternatives aux « droits d’auteur », certaines anciennes, d’autres plus récentes, ont été mises en place et s’inscrivent désormais dans ces nouvelles économies de services suscitées par la démocratisation du numérique. As digital technologies set off new modes of writing, listening, exchanging, circulating and data storaging, as well as new forms of authority, economies and types of relationships to time and to the world, this set of texts questions notions of musical and choreographic creation in our globalized context. Through a series of case studies which go beyond the North/South, written/oral, learned/popular and sacred/secular dichotomies, we better understand how these practices participate in the same regime of creation which either integrates or puts in tension two logics, one of renewal, another one of innovation. These practices of composing and recomposing are also questioned in terms of regimes of authority. The interest of this approach is to show that, in various regions of the world, alternative solutions to “copyright” systems, certain old, others more recent, have been set up and are henceforth part of the new service economies sparked off by the democratization of digital technologies