The effect of aCSF (a), DEX (b), or XJB (c) on electrically evoked DA responses measured before implanting the probe (blue lines), 2 h and 40 min after implanting the probe (red lines, the response was non-detectable in a), and 25 min after nomifensine (green lines). The solid lines are the average of the responses in each group of rats (n=6 per group) and the broken lines are confidence intervals based on the standard error of the mean of each data point. The black diamonds show when the stimulus begins and ends.