RESTRAINT STRESS-INDUCED ENHANCEMENT OF GLUTAMATE TRANSMISSION WITHIN NUCLEUS ACCUMBENS CORE AFTER EXTINCTION OF COCAINE-CONDITIONED PLACE PREFERENCE: AN IN VIVO MICRODIALYSIS STUDY

GUZMAN A; EULIARTE P.V.; AVALOS, M.P.; SANCHEZ, M.; OLIVEROS LEANDRO; RIGONI D; BOLLATI, FLAVIA A.; CANCELA LM.

Cordoba

Congreso; XXXIII Congress of the Argentine Society for Research in Neuroscience; 2018

Sociedad Argentina de Investigación en Neurociencias.

Stress is considered an important factor that induces relapse in human addicts and in animal models of addiction. Findings of our labdemonstratedpharmacologically therole of glutamatergic transmissionwithin Core,and not Shell, subcompartment of nucleus accumbens (NAc)in restraint stress-induced reinstatement of extinguished cocaine-conditioned place preference (CPP). The presentin vivo microdialysis study aims to evaluatethe effect of a single restraint stresssessionon extracellular levels of glutamate (GLU) in NAc Coreduringa re-exposureto the drug-paired context after extinction of cocaine-CPP. For this, male Wistar rats trained to acquire and then to extinguish cocaine-CPP, were stereotaxically implanted with self-built microdialysis probes. The next day, GLU dialysate samples were collected in the experimental room, first in the home cage to determine basal levels and thenin the cocaine-paired context after the exposure to restraint stress(30 min). Dialysate samples were quantified by HPLC coupled with electrochemical detection. Results indicate that animals submitted to restraint stress, showeda significantincreasein extracellular GLUlevels in NAc Core during the first 15 min of re-exposure to cocaine-paired context while the non-stress group did not show such increase.These findings could be explained in the framework of a dysregulation of GLU homeostasis induced by stress and provides neurochemical basis to investigate mechanisms underpinning relapse.