
Keywords: GRP، پپتید آزاد کننده گاسترین; GRP, gastrin-releasing peptide; Grpr, gastrin-releasing peptide receptor; ANOVA, analysis of variance; Maoa, monoamine oxidase A; MOP-r, mu opioid receptors; Npy5r, neuropeptide Y receptor 5oxycodone; adolescent; adult; self administration; neurotransmitt