mise à jour du
28 janvier 2010
Liste des orateurs
Les résumés par thème
Programme et horaires pdf   
FICY dans les médias
Index du site
Recherche par thèmes
Recherche par mot du site :


avec l'aide de


Première conférence internationale sur le bâillement
First International Conference on Yawning
Paris 24 - 25 juin 2010
Galerie des Photos de FICY
 colin deransart
Increased dopaminergic tone in Genetic Absence Epilepsy Rats from Strasbourg (GAERS): evidence from quinpirole-induced yawning and microdialysis experiments
Institution Grenoble - Institut des Neurosciences Centre de recherche Inserm U 836-UJF-CEA-CHU Equipe 9: Dynamique des Réseaux Synchrones Epileptiques
*Equipe 10: Dynamique des Réseaux Neuronaux du Mouvement Université Joseph Fourier - Faculté de Médecine Domaine de la Merci 38700 La Tronche
Purpose : In rats with absence epilepsy (GAERS), systemic and intrastriatal dopamimetics suppress seizures, whereas antagonists aggravate them. In addition, D3 receptor transcripts are overexpressed in the nucleus accumbens core (NacC) as compared to inbred non epileptic control rats (NEC). The hypothesis of an increased dopaminergic tone in GAERS was thus addressed using pharmacology and microdialysis.
Method: In GAERS and NEC (i) spontaneous and quinpirole-induced yawning behaviour and (ii) changes in intra-accumbens dopamine contents induced by amphetamine and K and measured by microdialysis were investigated. Results: Spontaneous yawning was significantly decreased in GAERS (0.3±0.2 yawn/hr, n=9) as compared to NEC (5.4±1.2, n=8) and Wistar Harlan rats (9.7±2.3, n=7). Quinpirole-induced yawning was significantly increased in GAERS (29.4±4.9) as compared to NEC (10.5±2.7) and Wistar-Harlan rats (22.6±3.5). Quinpirole also increased the number of absence-seizures in GAERS (+47.4±8.6%). When compared to NEC, basal levels of DA were 40% lower in GAERS whereas amphetamine and K produced a higher increase in extracellular dopamine in GAERS.
Conclusion : The increased quinpirole-induced yawning in GAERS may account for an overexpression in D3 transcripts. The increased responsiveness of dopamine transmission observed in GAERS after pharmacological manipulations, as compared to NEC, suggests a « hyperdopaminergic » phenotype of GAERS. Altogether, these data support that GAERS have an impaired DA tone that may be associated with the development of mechanisms controlling absences seizures