Pour savoir comment effectuer et gérer un dépôt de document, consultez le « Guide abrégé – Dépôt de documents » sur le site Web de la Bibliothèque. Pour toute question, écrivez à corpus@ulaval.ca.
 

Personne :
Tremblay, Pierre-Olivier

En cours de chargement...
Photo de profil

Adresse électronique

Date de naissance

Projets de recherche

Structures organisationnelles

Fonction

Nom de famille

Tremblay

Prénom

Pierre-Olivier

Affiliation

Département de médecine, Faculté de médecine, Université Laval

ISNI

ORCID

Identifiant Canadiana

ncf11849603

person.page.name

Résultats de recherche

Voici les éléments 1 - 1 sur 1
  • PublicationRestreint
    Effects of cocaine on c-fos and NGFI-B mRNA expression in transgenic mice underexpressing glucocorticoid receptors
    (American College of Neuropsychopharmacology, 2003-03-10) Tremblay, Pierre-Olivier; St-Hilaire, Michel; Barden, Nicholas; Lévesque, Daniel; Rouillard, Claude
    Numerous evidences suggest that stress and stress-related hormones can modulate the activity of the brain reward pathway and thus may account for individual vulnerability towards the reinforcing effects of drugs of abuse. Transgenic (TG) mice expressing an antisense mRNA against the glucocorticoid receptor (GR), which partially blocks GR expression, were used to assess the role of GR dysfunction on cocaine (COC)-induced c-fos and Nerve-Growth Factor Inducible-B (NGFI-B, or Nur77) gene expression. These two genes belong to different families of transcription factors and have been shown to be modulated by various dopaminergic drugs. TG and wild-type (WT) mice were both acutely and repeatedly treated with COC (20 mg/kg, i.p.). In the chronic experiment, mice received a 5-day treatment of COC and were challenged 5 days later with COC or vehicle. Locomotor activity was assessed during the entire chronic experiment in the mouse home cages. Animals were sacrificed 1 h after the last injection and NGFI-B and c-fos mRNA levels in the prefrontal cortex, the nucleus accumbens and the striatum were measured by in situ hybridization. Acute COC administration led to significantly smaller c-fos increases in TG mice compared to WT, whereas repeated COC treatment potentiated c-fos induction both in TG and WT mice to equivalent levels. TG mice displayed higher basal NGFI-B expression in the nucleus accumbens and the level of NGFI-B mRNA was differently modulated by COC in TG mice compared to WT mice. In accordance with data on c-fos expression, behavioral data indicate a blunted locomotor effect on the first COC injection in TG mice, a phenomenon corrected by the repeated COC treatment. These results suggest that an alteration of the hypothalamus-pituitary-adrenal axis can modify COC-induced regulation of the transcription factors c-fos and NGFI-B, and that these changes parallel those seen at the behavioral level. It also demonstrates that the differences at the behavioral and molecular levels noted between TG and WT mice after acute COC injection disappear following repeated COC administration, suggesting that repeated COC has a greater impact in TG mice underexpressing GRs.