Fig. 2.

Time course of the nicotine-mediated reduction in haloperidol-induced VCMs. Rats were implanted with minipumps containing vehicle or nicotine (2 mg/kg per day). Two weeks later, a subset of rats receiving vehicle or nicotine was injected subcutaneously once daily with haloperidol (1 mg/kg). They were then evaluated for the development of VCMs at the indicated time points as described under Materials and Methods. Nicotine treatment significantly reduced the severity of haloperidol-induced VCMs. Values are the mean ± S.E.M. of six rats in the vehicle and nicotine-treated and 12 rats in the haloperidol and nicotine + haloperidol-treated groups. Significance of difference from the vehicle-treated control, #, P < 0.05, ##, P < 0.01, ###, P < 0.001; from the haloperidol-treated group, *, P < 0.05, **, P < 0.01, ***, P < 0.001 using two-way ANOVA followed by a Bonferroni's post hoc test.