Figure 2.

Effects of prazosin pretreatment (0.5 and 1 mg/kg, i.p. 30 min before the session) on self-administration of nicotine (0.03 mg/kg/injection) (a) or food pellets (b) under a FR5 schedule during three consecutive daily sessions. Data are expressed as means (±SEM) of the number of injections or food pellets that the rats received during baseline conditions (BL), during three consecutive sessions with prazosin pretreatment (0.5 and 1 mg/kg) and during three consecutive sessions with vehicle pretreatment and saline substitution (only for nicotine self-administration). N=14 for nicotine self-administration; N=11 for food self-administration. ^*p<0.05; ^**p<0.01, ^***p<0.001 vs baseline (BL), Dunnett's test after significant ANOVA for repeated measures.