Figure 2.

Mecamylamine blocks the escalation of alcohol self-administration. Dependent rats were injected with mecamylamine (1 mg/kg, i.p.) or saline 45 min before each nicotine (0.8 mg/kg, s.c.) injection once per day, 15 min before each operant session after 6–8 h of withdrawal from alcohol vapor. The data represent the mean ± SEM number of active lever presses for 10% w/v alcohol in dependent rats treated with nicotine + saline (n = 7; black circles) or nicotine + mecamylamine (n = 7; black squares). *p < 0.05, compared with nicotine + saline group; ^#p < 0.05, compared with baseline.