Figure 2.
2-AG self-administration in nicotine-experienced monkeys over consecutive sessions. A, B, Number of injections per session (A) and overall rates of responding (B) in the presence of a green light during 30 μg/kg/injection nicotine sessions (sessions 1–5, closed circles), vehicle sessions (sessions 6–10, open circles), and 2-AG 3 μg/kg/injection sessions (sessions 11–15, closed circles) are shown. Points represent means ± SEM from four subjects. **p < 0.01, post hoc comparisons with the last session before vehicle extinction (session 5).