Involvement of actin rearrangements within the amygdala and the dorsal hippocampus in aversive memories of drug withdrawal in acute morphine-dependent rats.
J Neurosci
; 29(39): 12244-54, 2009 Sep 30.
Article
em En
| MEDLINE
| ID: mdl-19793983
ABSTRACT
Aversive memories of drug withdrawal can generate a motivational state leading to compulsive drug taking. Changes in synaptic plasticity may be involved in the formation of aversive memories. Dynamic rearrangement of the cytoskeletal actin, a major structural component of the dendritic spine, regulates synaptic plasticity. Here, the potential involvement of actin rearrangements in the induction of aversive memories of morphine withdrawal was examined. We found that lesions of the amygdala or dorsal hippocampus (DH) but not nucleus accumbens (NAc) impaired conditioned place aversion (CPA) of acute morphine-dependent rats. Accordingly, conditioned morphine withdrawal induced actin rearrangements in the amygdala and the DH but not in the NAc. In addition, we found that conditioned morphine withdrawal also increased activity-regulated cytoskeletal-associated protein (Arc) expression in the amygdala but not in the DH, although actin rearrangements were observed in both areas. We further found that inhibition of actin rearrangements by intra-amygdala or intra-DH injections of latrunculin A, an inhibitor of actin polymerization, significantly attenuated CPA. Furthermore, we found that manipulation of amygdala beta-adrenoceptor activity by its antagonist propranolol and agonist clenbuterol differentially altered actin rearrangements in the DH. Therefore, our findings reveal that actin rearrangements in the amygdala and the DH are required for the acquisition and consolidation of the aversive memories of drug withdrawal and that the beta-noradrenergic system within the amygdala modulates aversive memory consolidation by regulating actin rearrangements but not Arc protein expression in the DH, which is distinct from its role in modulation of inhibitory avoidance memory.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aprendizagem da Esquiva
/
Síndrome de Abstinência a Substâncias
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Actinas
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Hipocampo
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Tonsila do Cerebelo
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Dependência de Morfina
Limite:
Animals
Idioma:
En
Revista:
J Neurosci
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
China