Lack of effect of different pain-related manipulations on opioid self-administration, reinstatement of opioid seeking, and opioid choice in rats.
Psychopharmacology (Berl)
; 238(7): 1885-1897, 2021 Jul.
Article
em En
| MEDLINE
| ID: mdl-33765177
ABSTRACT
RATIONALE AND OBJECTIVE:
Pain-related factors increase the risk for opioid addiction, and pain may function as a negative reinforcer to increase opioid taking and seeking. However, experimental pain-related manipulations generally do not increase opioid self-administration in rodents. This discrepancy may reflect insufficient learning of pain-relief contingencies or confounding effects of pain-related behavioral impairments. Here, we determined if pairing noxious stimuli with opioid self-administration would promote pain-related reinstatement of opioid seeking or increase opioid choice over food.METHODS:
In Experiment 1, rats self-administered fentanyl in the presence or absence of repeated intraplantar capsaicin injections in distinct contexts to model context-specific exposure to cutaneous nociception. After capsaicin-free extinction in both contexts, we tested if capsaicin would reinstate fentanyl seeking. In Experiment 2, rats self-administered heroin after intraperitoneal (i.p.) lactic acid injections to model acute visceral inflammatory pain. After lactic acid-free extinction, we tested if lactic acid would reinstate heroin seeking. In Experiment 3, we tested if repeated i.p. lactic acid or intraplantar Complete Freund's Adjuvant (CFA; to model sustained inflammatory pain) would increase fentanyl choice over food.RESULTS:
In Experiments 1-2, neither capsaicin nor lactic acid reinstated opioid seeking after extinction, and lactic acid did not increase heroin-induced reinstatement. In Experiment 3, lactic acid and CFA decreased reinforcement rate without affecting fentanyl choice.CONCLUSIONS:
Results extend the range of conditions across which pain-related manipulations fail to increase opioid seeking in rats and suggest that enhanced opioid-addiction risk in humans with chronic pain involves factors other than enhanced opioid reinforcement and relapse.Palavras-chave
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Dor
/
Reforço Psicológico
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Medição da Dor
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Comportamento de Escolha
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Comportamento de Procura de Droga
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Analgésicos Opioides
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Psychopharmacology (Berl)
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Estados Unidos