Figure 3.

Locomotor response to cocaine in WT and SERT Met172 mice. Acute locomotor activity after 20 mL·kg⁻¹ saline i.p. (A) and 15 mg·kg⁻¹ cocaine i.p. (B) was not different between WT and SERT Met172 mice (two‐way RM‐ANOVA). I.p. injections were administered at time point 0. (C, D) Locomotor activity presented as average distance travelled in 10 min blocks during 50 min post injection normalized to individual baseline activities recorded 10 min prior to the injection. Surround and centre zone in the open field test were differentiated. No genotype differences were observed after saline treatment (C). After cocaine treatment (D), SERT Met 172 mice showed less ambulation in the centre zone than WT mice. Significant interaction effect but main drug and zone effect were not significant. Normalized locomotion is average distance travelled during 30 min post injection divided by average distance during 10 min prior to injection. Data plotted are means ± SEM, n = 27 (WT), 20 (Met172), *P < 0.05, signficantly different as indicated; two‐way ANOVA with Sidak's post hoc test.