Brief social defeat stress: long lasting effects on cocaine taking during a binge and zif268 mRNA expression in the amygdala and prefrontal cortex.
Neuropsychopharmacology
; 30(2): 310-21, 2005 Feb.
Article
em En
| MEDLINE
| ID: mdl-15496936
ABSTRACT
Social stress can engender behavioral and neural sensitization and this process appears to enhance the transition to compulsive drug abuse. Exposures to brief social defeat stress in rats have significant consequences on cocaine-reinforced behavior and on the level of functional activation within regions of the mesocorticolimbic dopamine system. The objectives of the current study were to examine the enduring consequences of brief episodes of social defeat stress on cocaine bingeing (during 24 h of continuous access) and on the emergence of neural adaptations as revealed by zif268 immediate early gene expression. Adult, male Long-Evans rats were subjected to four 25 min episodes of social defeat (once every 72 h). After 2 months, cocaine binges or zif268 mRNA gene expression were studied after confirming behavioral cross-sensitization to stimulant challenge. Sensitization to social defeat increased cocaine intake during a 24 h binge, effectively abolishing the typical circadian pattern of intake. Furthermore, 60 days after exposure to the sensitizing regimen of social defeat, levels of functional activation, measured by zif268 mRNA expression, in the central and medial amygdala were increased, while levels of activation in the medial prefrontal cortex were decreased. Persistent stress-induced levels of zif268 in the central and medial amygdala were attenuated by an injection of amphetamine (1.0 mg/kg). Divergent changes in zif268 within the amygdala and cortex 2 months after social defeat stress indicate the vulnerability of distinct cellular populations in networks that modulate the behavioral actions of psychomotor stimulants.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Meio Social
/
Estresse Psicológico
/
Fatores de Transcrição
/
Córtex Pré-Frontal
/
Cocaína
/
Proteínas Imediatamente Precoces
/
Transtornos Relacionados ao Uso de Cocaína
/
Proteínas de Ligação a DNA
/
Tonsila do Cerebelo
Aspecto:
Determinantes_sociais_saude
Limite:
Animals
Idioma:
En
Revista:
Neuropsychopharmacology
Ano de publicação:
2005
Tipo de documento:
Article