%0 Journal Article %A Pavon, Francisco J %A Polis, Ilham %A Stouffer, David G %A Roberto, Marisa %A Martin-Fardon, Remi %A RodrIguez de Fonseca, Fernando %A Parsons, Loren H %A Serrano, Antonia %T COX-2 Inhibition Antagonizes Intra-Accumbens 2-Arachidonoylglycerol-Mediated Reduction in Ethanol Self-Administration in Rats. %D 2020 %U http://hdl.handle.net/10668/16274 %X Ethanol (EtOH) self-administration is particularly sensitive to the modulation of CB1 signaling in the nucleus accumbens (NAc) shell, and EtOH consumption increases extracellular levels of the endogenous cannabinoid CB1 receptor agonist 2-arachidonoyl glycerol (2-AG) in this brain region. Stimulation of CB1 receptor with agonists increases EtOH consumption, suggesting that EtOH-induced increases in 2-AG might sustain motivation for EtOH intake. In order to further explore this hypothesis, we analyzed the alterations in operant EtOH self-administration induced by intra-NAc shell infusions of 2-AG itself, the CB1 inverse agonist SR141716A, the 2-AG clearance inhibitor URB602, anandamide, and the cyclooxygenase-2 (COX-2) inhibitor nimesulide. Surprisingly, self-administration of 10% EtOH was dose-dependently reduced by either intra-NAc shell SR141716A or 2-AG infusions. Similar effects were found by intra-NAc shell infusions of URB602, suggesting again a role for accumbal 2-AG on the modulation of EtOH intake. Intra-NAc shell anandamide did not alter EtOH self-administration, pointing to a specific role for 2-AG in the modulation of EtOH self-administration. Finally, the inhibitory effect of intra-NAc shell 2-AG on EtOH intake was significantly reversed by pretreatment with nimesulide, suggesting that oxidative metabolites of 2-AG might mediate these inhibitory effects on operant self-administration. We propose that 2-AG signaling in the NAc exerts an inhibitory influence on EtOH consumption through a non-CB1 receptor mechanism involving the COX-2 pathway. %K 2-Arachidonoyl glycerol %K Cyclooxygenase-2 %K Ethanol %K Nucleus accumbens %~