Orexin A in the ventral tegmental area induces conditioned place preference in a dose-dependent manner: Involvement of D1/D2 receptors in the nucleus accumbens

► Administration of orexin A in the VTA induced CPP in a dose-dependent manner in rat. ► Intra-accumbal D1 receptor antagonist reduced orexin-induced CPP in the VTA. ► Blocking D2 receptors in NAc dose-dependently reduced intra-VTA orexin-induced CPP. ► Intra-NAc administration of D1/D2 receptor antagonists alone could not induce CPP.