FIG. 4.

SERT-KO rats display delayed and attenuated horizontal movement velocity after a single dose of MDMA. Locomotor activity was measured by placing animals into open-field activity chambers. Baseline levels of locomotion were measured for 45 min, followed by a 120 min posttreatment period in which MDMA (10 mg/kg, sc) was administered. Figures show the mean (SE ± 6–10) horizontal (A) and vertical (B) activities at each time interval. Scatter plots display total horizontal velocity and total vertical activity over the entire 165 min treatment course. Values are significantly different from WT saline values at *p < 0.05, from SERT-KO saline values at ^#p < 0.05, and from WT MDMA values at ^ξp < 0.05.