Figure 8.

Dopamine uptake transporters regulate extracellular dopamine equally at the somatodendritic level across the VTA. A, Representative synaptic and exogenous currents recorded from NAc- and BLA-projecting neurons. IPSCs were evoked with monopolar glass electrodes by a train of five pulses (duration, 0.5 ms; 40 Hz). Iontophoretic currents were evoked by ejecting DA as a cation with a single pulse (20–150 nA; 25–100 ms) once every 60 s. Note the equal increase in amplitudes and the slowing of kinetics of both currents by the application of the nonspecific monoamine uptake inhibitor cocaine (1 μm) in both BLA- and NAc-projecting neurons. B, Summary data (normalized percentage change; mean ± SEM) from BLA- (n = 5) and NAc- (n = 7) projecting neurons. C, Summary of the kinetics of D₂ IPSCs recorded in BLA- (n = 6) and NAc- (n = 9) projecting VTA neurons. Stim, Stimulation.