Fig. (1).

Distinct responses to MPH in DAT^-/- mice. In the open field test, (A, B) DAT^-/- mice exhibited hyperactivity in a novel environment. (A, C) Methylphenidate (30 mg/kg, i.p.) inhibited locomotor activity in DAT^-/- mice (n = 9-16 per group). (D, E) 
DAT^-/- mice exhibited comparable escape activity when assessed in the tail suspension test. (D, F) The response to MPH (30 mg/kg, i.p.) was equal among the three genotypes (n = 8-14). *P < 0.05, **P < 0.01, vs DAT^+/+ mice (Scheffe’s test). The data are expressed as mean ± SEM.