Self-administration of agonists selective for dopamine D2, D3, and D4 receptors by rhesus monkeys.
Behav Pharmacol
; 23(4): 331-8, 2012 Aug.
Article
em En
| MEDLINE
| ID: mdl-22785383
ABSTRACT
Dopamine receptor mechanisms are believed to play a role in the reinforcing effects of cocaine and other drugs of abuse. The lack of receptor-selective agonists has made it difficult to determine the role of the individual dopamine receptors in mediating these reinforcing effects. In this study, rhesus monkeys with a history of intravenous cocaine self-administration were tested for the reinforcing effects of several D(3)-preferring agonists, a D(2)-preferring agonist, and a D(4) agonist. The D(2)-preferring agonist did not maintain responding in any monkeys, and the D(4) agonist was self-administered at low rates, just above those maintained by saline, in one monkey. The D(3)-preferring agonists were self-administered by approximately half of the animals, although at lower rates than cocaine. These results indicate that the apparent limited reinforcing effectiveness of D(2)-like agonists requires activity at D(3) receptors. Previous data from this laboratory and others also suggest that these drugs may not serve as reinforcers directly; the behavior may be maintained by response-contingent delivery of stimuli previously paired with cocaine. The ability of drug-related stimuli to maintain responding apparently differs among monkeys and other organisms, and may be related to individual differences in drug-taking behavior in humans.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Comportamento Animal
/
Cocaína
/
Agonistas de Dopamina
Limite:
Animals
Idioma:
En
Revista:
Behav Pharmacol
Assunto da revista:
CIENCIAS DO COMPORTAMENTO
/
FARMACOLOGIA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos