Effects of neonatal MK-801 treatment on running wheel performance. Rats were dosed with 0, 0.025, 0.05, 0.1, 0.15, 0.2, or 0.25 mg/kg and tested at a weanling age. Data are average number of revolutions per 15 min. The significance of differences from the saline-treated group was determined through a repeated measures ANOVA followed by Bonferroni correction. ∗, P < 0.05