Fig. 6.
D1-dopamine receptors have two effects in withdrawn slices: increased adenosine tone and increased GABA release. The top shows examples of IPSPs from four different cells. In each example, three superimposed IPSPs are illustrated: the control, in the presence of SKF82958 (1 μm), and after treatment with SCH23390 (1 μm). The top traces are taken from control (left) and withdrawn (right) slices. The bottom traces are also taken from control (left) and withdrawn (right) slices, however in these experiments the slices had been treated with DPCPX (1 μm). The bar graph at the bottom shows summarized data indicating that the increase in the GABAB IPSP by SKF82958 in control slices was not changed by DPCPX, whereas in withdrawn slices it was significantly increased. Similar results were obtained with the D1 antagonist SCH23390 (1 μm). In this case, SCH23390 had no effect on the IPSP in control but significantly increased the IPSP in withdrawn slices treated with DPCPX.