Adolescent-onset of cocaine use is associated with heightened stress-induced reinstatement of cocaine seeking.
Addict Biol
; 21(3): 634-45, 2016 May.
Article
em En
| MEDLINE
| ID: mdl-26202521
ABSTRACT
Adolescent rats take cocaine more readily than adults, are more sensitive to lower doses of the drug and work harder for it. It remains unknown if adolescent-onset of cocaine use has long-term consequences on adult relapse liability. Therefore, we tested if self-administering cocaine during adolescence impacts subsequent stress-induced reinstatement to cocaine seeking and taking, after a prolonged drug-free period. Adolescent (~P42) or adult (P88) rats self-administered cocaine (0.6 or 1.2 mg/kg/infusion) for 7 or 10 days. Then, they underwent a prolonged drug-free period (21-40 days), after which they were tested for reinstatement of cocaine-seeking (i.e. responding in the absence of cocaine) induced by the stress hormone corticosterone, the pharmacological stressor yohimbine or electric footshock. Studies employed either single extinction session (within-session extinction/reinstatement) or repeated extinction prior to reinstatement (between-session extinction/reinstatement). Finally, in a separate set of experiments, rats underwent a prolonged drug-free period (~40 days) and were then allowed to self-administer cocaine again, using progressive-ratio procedures that appraise the reinforcing efficacy of cocaine. Rats with adolescent-onset of cocaine use showed greater stress-induced reinstatement of cocaine seeking than rats with adult-onset of cocaine use. This was observed across conditions, providing external validity to these results. Groups did not differ on drug taking in progressive-ratio tests. Our studies indicate that experiencing cocaine during adolescence renders subjects particularly responsive to the subsequent effects of stress on drug seeking. This heightened propensity for reinstatement puts adolescent-onset drug users at heightened risk for relapse.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Reforço Psicológico
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Estresse Psicológico
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Cocaína
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Inibidores da Captação de Dopamina
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Transtornos Relacionados ao Uso de Cocaína
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Comportamento de Procura de Droga
Tipo de estudo:
Prognostic_studies
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Risk_factors_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article