Inhibitory effects of dopamine and methylenedioxymethamphetamine (MDMA) on glutamate-evoked firing of nucleus accumbens and caudate/putamen cells are enhanced following cocaine self-administration.
Brain Res
; 681(1-2): 167-76, 1995 May 29.
Article
em En
| MEDLINE
| ID: mdl-7552276
ABSTRACT
Rats were allowed to self-administer cocaine during a 3-h session for 15 days. One to 11 days after the last cocaine exposure, rats were anesthetized with urethane and effects of microiontophoretically-applied dopamine on glutamate-evoked firing of neurons in the nucleus accumbens and in the caudate/putamen were tested. Dopamine produced a dose-dependent inhibition of glutamate-evoked firing in both the nucleus accumbens and the caudate/putamen of rats that had been repeatedly exposed to self-administered cocaine and in control rats. However, the DA-induced inhibition was significantly greater in the group that had self-administered cocaine. The cocaine self-administration group was significantly sensitized to the inhibitory effects of dopamine in both early (1-3 day) and later (9-11 days) periods of cocaine abstinence. Following cessation of repeated cocaine self-administration sessions, nucleus accumbens cells were also sensitized to the inhibitory effects of methylenedioxymethamphetamine (MDMA), a drug that increases extracellular levels of DA and serotonin in the nucleus accumbens. This sensitization to DA- and MDMA-induced inhibition in the nucleus accumbens and in the striatum indicates that long-term neuroadaptations occur in these regions of the nervous system following repeated exposure to self-administered cocaine.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Encéfalo
/
Dopamina
/
Cocaína
/
N-Metil-3,4-Metilenodioxianfetamina
/
Ácido Glutâmico
/
Inibidores da Captação de Dopamina
/
Neurônios
Limite:
Animals
Idioma:
En
Revista:
Brain Res
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Estados Unidos