CONTEXT-SPECIFIC INCREASE OF GLUTAMATE TRANSMISSION IN COCAINE- CONDITIONED PLACE PREFERENCE: AN IN VIVO MICRODIALYSIS STUDY

EULIARTE P. V.; GUZMAN, A.S.; AVALOS M. P.; SANCHEZ M. A.; OLIVEROS, L.; RIGONI, D.; BOLLATI, F.; CANCELA, L. M.

Córdoba

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

Argentine Society for Research in Neurosciences

The conditioned place preference (CPP) paradigm results suitable to evaluate the neurobiological changes induced by a cocaine-associated context in absence of the drug. Specifically, pharmacological evidence from our lab demonstrated the role of glutamatergic transmission within the nucleus accumbens (NAc) in different phases of cocaine- CPP. The aim of the present study was to evaluate in vivo changes in extracellular glutamate (GLU) levels in NAc as a result of cocaine conditioning and extinction. For this, a microdialysis assay was performed in male Wistar rats trained to acquire, and then to extinguish, cocaine-induced CPP. Animals were stereotaxically implanted with microdialysis probes and then GLU dialysate samples were collected in the experimental room, first in the home cage to determine basal levels and then in the cocaine-paired or in the unpaired context. Dialysate samples were quantified by HPLC coupled with electrochemical detection. Results indicate that the enhancement of GLU is specific for the cocaine-paired context since animals evaluated before conditioning or in the unpaired context did not show such increase during re-exposure to the context. Furthermore, the increase of GLU was not either observed following extinction of cocaine-CPP. These findings support the idea that pairing cocaine with a specific context can modulate glutamate transmission in nucleus accumbens influencing cocaine-seeking behavior and this can disappear after extinction of drug-CPP