Fig. 1.

METH preincubation at various concentrations decreased [³H]DA uptake. Striatal synaptosomes were preincubated with various concentrations of METH (in μm: 1–100) or assay buffer for 30 min at 37°C and later assayed at 37°C for the influx of [³H]DA. Before assaying DA influx, synaptosomal preparations were washed two extra times, as described in Materials and Methods. Values represent means, and vertical lines are 1 SEM of determinations from three independent experiments. Asterisks indicate values for METH-treated synaptosomes that differ significantly from controls (p ≤ 0.05).