Fig. 1.
Monosynaptic IPSPs are depressed by amphetamine and dopamine. A, B, In DNQX (10 μm) and APV (75 μm), IPSPs recorded with a potassium methylsulphate-based electrode solution exhibited a linear dependence on membrane potential and reversed at the estimated Cl− reversal potential of −58 mV.C, The traces depict the effects of picrotoxin (50 μm) on IPSPs recorded at 0 mV. In this, and subsequent, figures, the negative voltage deflection after the synaptic potential is the result of a −0.03 nA current pulse given through the recording electrode. The traces are averages of consecutive sweeps taken at the times indicated by the numbers in the bottom graph, which demonstrates the time course of experiment. D, Representative IPSP traces (top) taken from one experiment before application of amphetamine, in the presence of bath-applied amphetamine (10 μm) and after recovery of the response. The bottom graph is a normalized average (n = 10) of the time course of the effects of amphetamine on IPSPs. Error bars (this and subsequent graphs) indicate SEM. E, The traces are taken from one experiment during the baseline, before application of dopamine (75 μm), and during recovery. The bottom graph is an average (n = 28) demonstrating that dopamine reversibly depressed the IPSP.