Effect of cocaine on locomotor activity in DAT-KD mutant mice compared to WT mice. Mice were habituated to the locomotor test chamber for 60 minutes. Cocaine or saline were injected (ip) and mice were returned to the test chamber and monitored for another 60 min. A) and B): Time course of locomotor activity of WT mice and DAT-KD mice. Saline, 5 mg/kg, 10 mg/kg or 20 mg/kg cocaine was given at the time indicated by the arrows. Data shown are average distance traveled in 5 min. C) Total distance traveled in 60 minutes for wild type and DAT-KD mice during their habituation to the chambers before drug or saline injection. DAT-KD mice are significantly more active than wild type ice (***, p < 0.001, t-test). D) Total distance traveled in 30 min after the injection of saline or 5, 10, or 20 mg/kg cocaine with 6 – 8 mice in each group. Two-way ANOVA was performed. Cocaine significantly increased locomotor activities in both genotypes of mice (for drug effect, F3,66 = 22.38, p < 0.001) and had greater effect on DAT-KD mice than on the WT mice (for genotype, F1,66 = 19.57, p < 0.001). Error bars represent standard error of means. Post hoc Bonferroni tests versus saline: *, p < 0.05; **, p < 0.01; ***, p < 0.001. Comparing between the two genotypes, 5 mg/kg and 10 mg/kg cocaine had a greater effect on locomotor activity in the DAT-KD mice than in wild type mice (#, p < 0.01).
Tilley et al. BMC Neuroscience 2007 8:42 doi:10.1186/1471-2202-8-42