Typical voltammetric tracings of extracelluar DA concentration in dorsal striatum in unilaterally 6-OHDA lesioned rats. Examples of KCl -evoked dopamine release were taken from dorsal striatum (3.5 to 5 mm below brain surface). KCl (150–200 nL x 70 mM) was delivered locally through a micropipette next to DA sensor at time 0. (A) Local administration of KCl induced DA release in non-lesioned striatum (black tracing) in a vehicle treated animal. In the same animal, KCl-mediated DA release was almost abolished in lesioned striatum (red tracing). (B) In contrast, 9cRA treatment partially restored KCl –induced DA release in lesioned striatum in another animal. 9cRA did not alter DA release in the non-lesioned striatum. Note that slope between T20 and T60 (A) is used to calculate the rate of clearance in Figure 5B.