Figure 1. Inhibition by nicotine (5 μm) of currents generated by ATP (6 μm).

In this experiment, after a rough concentration-response curve was constructed for nicotine (A), a concentration of 5 μm nicotine was chosen to examine the interaction with 6 μm ATP (B). Note the complete occlusion of the inward current produced by 6 μm ATP in the presence of nicotine. The effect was fully reversible (C). Traces A, B and C were recorded continuously from the same cell. In all figures, drugs were applied by rapid fast-flow superfusion during the period represented by the bar. The cell was held at -110 mV in the whole cell recording mode.