Taking Rapid and Intermittent Cocaine Infusions Enhances Both Incentive Motivation for the Drug and Cocaine-induced Gene Regulation in Corticostriatal Regions.
Neuroscience
; 442: 314-328, 2020 08 21.
Article
en En
| MEDLINE
| ID: mdl-32682656
ABSTRACT
A goal in addiction research is to distinguish forms of neuroplasticity that are involved in the transition to addiction from those involved in mere drug taking. Animal models of drug self-administration are essential in this context. Here, we compared in male rats two cocaine self-administration procedures that differ in the extent to which they evoke addiction-like behaviours. We measured both incentive motivation for cocaine using progressive ratio procedures, and cocaine-induced c-fos mRNA expression, a marker of neuronal activity. Rats self-administered intravenous cocaine (0.25â¯mg/kg/infusion) for seven daily 6-hour sessions. One group had intermittent access (IntA; 6 minutes ON, 26â¯min OFFâ¯×â¯12) to rapid infusions (delivered over 5â¯s). This models the temporal kinetics of human cocaine use and produces robust addiction-like behaviour. The other group had Long access (LgA) to slower infusions (90â¯s). This produces high levels of intake without promoting robust addiction-like behaviour. LgA-90â¯s rats took twice as much cocaine as IntA-5â¯s rats did, but IntA-5â¯s rats showed greater incentive motivation for the drug. Following a final self-administration session, we quantified c-fos mRNA expression in corticostriatal regions. Compared to LgA-90â¯s rats, IntA-5â¯s rats had more cocaine-induced c-fos mRNA in the orbitofrontal and prelimbic cortices and the caudate-putamen. Thus, a cocaine self-administration procedure (intermittent intake of rapid infusions) that promotes increased incentive motivation for the drug also enhances cocaine-induced gene regulation in corticostriatal regions. This suggests that increased drug-induced recruitment of these regions could contribute to the neural and behavioural plasticity underlying the transition to addiction.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Preparaciones Farmacéuticas
/
Cocaína
/
Trastornos Relacionados con Cocaína
Límite:
Animals
Idioma:
En
Revista:
Neuroscience
Año:
2020
Tipo del documento:
Article
País de afiliación:
Canadá
Pais de publicación:
EEUU
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ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
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EUA
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UNITED STATES
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UNITED STATES OF AMERICA
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US
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USA