exert anxiolytic effects [39]. The present experiments were designed to exclude the apparatus bias over the conditioning phase by inclusion of saline-saline control animals. In agreement with our findings, the pharmacological approach using AMPA receptor antagonists suggests that these receptors are dispensable in drug-induced conditioned place preference, as long as the ligands are selective to the AMPA receptors and do not affect the NMDA receptor functions [37], [40], [41].
