Glu R2-3Y Inhibits the Acquisition and Reinstatement of Morphine-Induced Conditioned Place Preference in Rats

Accumulating evidence indicates that a-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors(AMPARs) are involved in the relapse to abused drugs.However, the role of AMPARs containing the Glu R2 subunit in opiate addiction is still unclear. Glu R2-3Y,an interfering peptide, prevents the endocytosis of AMPARs containing the Glu R2 subunit. In this study, we explored the effect of intravenous injection of Glu R2-3Y on the acquisition, expression, and reinstatement of morphine-induced conditioned place preference(m CPP) in rats. We found that infusion of Glu R2-3Y(1.5 nmol/g) one hour before morphine during the conditioning phase inhibited the acquisition of m CPP, while an identical injection one hour before the post-conditioning test had no influence on the expression of m CPP. Injection of Glu R2-3Y(1.5 nmol/g) after m CPP extinction blocked the morphine-induced reinstatement of m CPP. Our results strongly support the hypothesis that inhibition of AMPAR endocytosis provides a new target for the treatment of opiate addiction.