Activation of Cannabinoid CB1 Receptor within Nucleus Accumbens Core Underlies Restraint Stress-Induced Reinstatement in Extinguished Cocaine?Conditioned Animal

GUZMAN, A.S.; DE GIOVANNI, L.N.; VIRGOLINI, M.B.; CANCELA L.M.

Huerta Grande, Córdoba, Argentina.

Congreso; XXIX Congreso de la Sociedad Argentina de Investigación en Neurociencias; 2014

Sociedad Argentina de Investigación en Neurociencias

Endocannabinoid system is implicated in relapse in extinguished cocaine-conditioned animals. Moreover, Nucleus Accumbens (NAc), a high density cannabinoid CB1 receptors brain region, is involved in cocaine and stress-induced reinstatement. Previous results from our lab demonstrated that in extinguished cocaine-conditioned animals evaluated in a conditioned place preference test (CPP), the restraint-stress was able to reinstate the cocaine CPP and that phenomenon depends on the glutamatergic transmission within NAc. Additionally, in our lab it has been revealed that intra-Core administration of AM251, a CB1 antagonist, abrogated that restraint stress-induced reinstatement. According to the previous protocol, on the reinstatement test day, extinguished cocaine-conditioned Wistar rats were microinjected intra-Core with a CB1 agonist, ACEA, (0, 0.001 or 0.01 fmol/side) or vehicle, and subsequently assigned to the following treatments: 1) Stressed animals: 15 min-restraint exposure, a non-reinstatement session, and 2) Control animals. The administration of ACEA facilitated the restraint stress-induced reinstatement in extinguished cocaine-conditioned animals that were exposed to 15 min of stress. Our results support the hypothesis of the influence of CB1 receptors in restraint stress-induced reinstatement. Future studies will focus on a possible glutamate dependent mechanism within NAc Core to explain the effect of CB1 receptor activation on restraint stress-induced reinstatement