Figure 1: Standard experimental procedures for the operant extinction-reinstatement model. Self-administration sessions are typically conducted daily for limited (1-2 hr) exposure to methamphetamine reinforcement. This training typically lasts between seven [38,41] and 14 [76] days. This is followed by extinction training, which usually is continued until an extinction criterion is reached, usually requiring between five [49] and 14 [41,42] days, although the rate of extinction depends on whether cues are present or saline infusions are substituted for methamphetamine during this phase. Following the initial extinction period, a reinstatement test is performed following treatment by the test compound. Subsequent reinstatement tests are preceded by repeated daily extinction sessions, in order to reestablish the baseline responding.