CANNABINOID CB1 RECEPTORS WITHIN NUCLEUS ACCUMBENS SHELL ARE NOT INVOLVED IN STRESS-INDUCED REINSTATEMENT IN EXTINGUISHED COCAINE?CONDITIONED ANIMALS

GUZMAN A; DE GIOVANNI L; AVALOS, M.P.; BOLLATI FLAVIA; VIRGOLINI M; CANCELA LM.

Mar del Plata

Congreso; XXX SAN Annual Meeting; 2015

Sociedad Argentina de Investigación en Neurociencia.

Endocannabinoid system, primarily through their actions at CB1 receptor (CB1R), is implicated in drug relapse. Previous results from our lab demonstrated that in extinguished cocaine-conditioned animals, evaluated in a conditioned place preference test (CPP), the administration of AM251, a CB1R antagonist, or ACEA, a CB1R agonist, into the Core of the Nucleus Accumbens (NAc) abrogated or facilitated restraint stress-induced reinstatement of cocaine-CPP responses, respectively. In order to compare the involvement of both NAc compartments, extinguished cocaine-conditioned Wistar rats were microinjected into the Shell of NAc with ACEA (0.01fmol/side), AM251 (10ug/side) or vehicle, and subsequently assigned to the following treatments: 1) Stressed Animals (SA): 15 or 30 min-restraint exposure, depending on the experiment, and 2) Control Animals (CA). The intra-Shell administration of CB1R antagonist or agonist did not modify the restraint stress-induced reinstatement of cocaine-CPP responses as previously observed after intra-Core administration of CB1R ligands. These findings support the hypothesis of the preferential influence of CB1R within NAc Core, but not Shell, in the reinstatement of cocaine seeking behavior. Future studies will attempt to identify a possible glutamate dependent mechanism underpinning the effects of CB1R ligands on the restraint stress-induced reinstatement of cocaine-CPP responses.