A single METH administration rapidly decreases (within 0.5 h) VMAT-2M-mediated DA uptake; an effect that persists at least 3 h (A). Rats received an injection of METH (15 mg/kg, s.c.) and were killed 0.5, 1 or 3 h later. Other rats received an injection of saline vehicle (1 ml/kg, s.c.) and were killed 0.5 h later. Each column represents the mean ± S.E.M. of 6 to 8 independent determinations. *, indicates a statistical difference from saline-treated animals. A single METH-induced VMAT-2M-mediated DA uptake decrease recovers 24 h later (B). Rats received an injection of METH (15 mg/kg, s.c.) and were killed 1 or 24 h later. Other rats received an injection of saline vehicle (1 ml/kg, s.c.) and were killed 1 h later. Each column represents the mean ± S.E.M. of 6 to 8 independent determinations. *, indicates a statistical difference from saline-treated animals.