Figure 3.

Effect of LY379268 ([−]-2-oxa-4-aminobicyclo [3.1.0] hexane-4,6-dicarboxylate; 1 mg/kg) on nucleus accumbens (NAcc) shell dopamine after self-administration of a single intravenous infusion of nicotine (0.06 mg/kg per infusion over 1 s) in nicotine-experienced animals in a context associated with nicotine self-administration (Experiment 3a). Dopamine levels (mean±standard error of mean [SEM]) are expressed as a percentage of baseline values. ^*p<0.05, ^***p<0.001, saline-pretreated compared with their own baseline levels; and ⁺p<0.05, ⁺⁺p<0.01, ⁺⁺⁺p<0.001, saline-pretreated compared with LY379268-pretreated animals. (Inset) Latency (mean±SEM) in minutes to self-administer nicotine in saline- and LY379268-pretreated animals. ^**p<0.01, LY379268-pretreated group compared with saline-pretreated group. The time period between −10 and 10 depicts the time taken by the animals to self-administer nicotine and the dead volume of the probe (no samples were collected during that period). The time taken to self-administer nicotine varied among LY379268- and saline-pretreated animals. On the basis of the dead volume of the tubing, sample collection was initiated 2 min after nicotine self-administration in all animals.