MDPV-like discriminative stimulus effects (upper left panel) and response rate (lower left panel) of MDPV, α-PVP, α-PPP, MDPPP, MDPBP, methylone (left panels) and MDPV, caffeine, fentanyl, nicotine and cocaine (right panels) in rats trained to discriminate MDPV (1 mg/kg) from saline. All data are represented as the mean ±S.E.M (n=8 unless otherwise shown).