Figure 2.
Effects of αMPT (200 mg/kg, i.p.) followed by cocaine (10 mg/kg, i.p.) administration on stimulated dopamine release in WT (open circles) and synapsin TKO (filled triangles) mice. Dopamine release was electrically evoked by short (24 pulse, 60 Hz, every 2 min) stimulation trains except for the 100 min interval after αMPT when long (600 pulse, 60 Hz, every 20 min) stimulations were used to deplete dopamine stores, and dopamine was measured by constant potential amperometry. The stimulation pulses (p) in these time domains are indicated at the top of the figure. A, The peak neurochemical response ([DA]max) to 24- and 600-pulse stimulations as a percentage of the predrug values. B, Km values obtained from modeling of the experimental data expressed as a percentage of the predrug values. C, [DA]p values obtained by neurochemical modeling of the experimental data expressed as a percentage of the predrug value. The data are presented as the mean ± SEM from measurements in eight animals for each genotype.