Figure 4.

Effect of cholinergic cell elimination on cocaine-induced CPP. CPP developed by repeated cocaine administration was analyzed in animals 2 weeks after bilateral IT injection into the NAc (n = 8–14). Before and after conditioning was performed with indicated doses of i.p. cocaine injection for 3 days; the time difference was calculated by subtracting time mice spent in the saline-paired side from time they spent in the cocaine-paired side. Columns and error bars represent mean ± SEM, respectively. Cholinergic cell-eliminated transgenic mice spent significantly more time in the cocaine-paired side after conditioning with 5 mg/kg and 10 mg/kg of cocaine (**, P < 0.01).