Fig. 2.
P2X receptor antagonists variably block the P2X receptor-mediated EPSCs in lamina II neurons.A, ATP-mediated EPSCs were tested for the degree of suramin block. Fast EPSCs were recorded from a P10 neuron in CABS. Application of 500 μm suramin (CABS + Sur) completely blocked the EPSC. A complete recovery was observed after suramin washout. EPSCs are averages of 10 consecutive traces.B, ATP-mediated EPSCs were tested for the degree of PPADS block. EPSCs were recorded from a lamina II neuron (P6) in CABS. Bath application of 100 μm PPADS (CABS + PPADS) incompletely blocked the EPSC. Partial recovery was obtained after a 10 min wash in CABS. EPSCs are averages of 13–15 consecutive traces. C, P2X receptor-mediated EPSCs were tested for sensitivity to both suramin and PPADS. EPSCs were evoked in a P11 lamina II neuron in the presence of CABS. Suramin (500 μm) (CABS + Sur) partially blocked the EPSC. After a wash in CABS the suramin-blocked component recovered. Application of 50 μm PPADS (CABS + PPADS) slightly depressed the EPSC amplitude. EPSCs are averages of 20 consecutive traces. Data for all three cells are shown with holding currents subtracted. In all cases, holding current varied <10 pA throughout the recording period.