Fig. 8. EPSPs supported by 2 mm glucose, but not by 10 mm glucose, are sensitive to 4-CIN.a, Although changing the glucose concentration from 10 mm to 2 mm does not alter baseline EPSPs (Izumi and Zorumski, 1997), administering 200 μm 4-CIN (filled bar) in the presence of 2 mmglucose depresses EPSPs. EPSPs recover after drug washout even in the presence of 2 mm glucose. Representative EPSPs in the presence of 10 mm glucose, 30 min after reducing the glucose concentration to 2 mm (time 0), 20 min after administration of 4-CIN, and 30 min after washout (time 50) are shown to the right of the graphs. b, Administration of 200 μm 4-CIN (filled bar) does not depress EPSPs supported by 10 mmglucose (see Figs. 4, 5). However, lowering the glucose concentration to 2 mm for 30 min (time 0–30) depresses EPSPs in the presence of 4-CIN. This depression is reversed by reperfusion with 10 mm glucose (time 30–50). The traces depict representative field EPSPs before and 30 min after administration of 4-CIN (time −30 and 0), 20 min after lowering glucose concentration, and 20 min after returning the glucose concentration to 10 mm (time 50). Calibration bar, 1 mV, 5 msec.