Methamphetamine-induced locomotor changes are dependent on age, dose and genotype

► High dose METH caused significant total distance sensitization in B6 adolescents. ► Low dose METH produced significant tolerance for vertical activity in B6 adults. ► Low dose METH induced significant sensitization for vertical activity in D2 adults. ► Adolescent and adult 129 mice metabolized METH faster than the B6 and D2 strains.