Figure 1:

Methylone self-administration in male Sprague-Dawley rats. (A) Mean±SEM of the total responses emitted on the active (filled symbols) or inactive (Xs) lever during the active portion of the 90-minute session (n=42 rats). (B) Cumulative percent of rats to acquire self-administration of 0.32 mg/kg/infusion methylone across the 10-day acquisition period. Abscissa: numbers refer to consecutive days during the acquisition period. (C) Dose-response curve for methylone self-administration obtained in rats (n=21) under the FR5 schedule of reinforcement. Abscissa: SAL represents infusions of saline, while the numbers refer to dose of methylone available during each session, expressed as mg/kg/inf on a log scale. Ordinate: Mean±SEM of the total infusions earned during the 90-minute session.