Figure 2.

Analysis of changes in voltage-dependence of TTX-sensitive currents by indomethacin and β-bungarotoxin. 2A: Effect of β-BuTX on voltage-dependence by current/voltage-relationships: currents were normalized to the maximal current amplitude and plotted against the potentials of the electrical stimulation. Curves were fitted using the Boltzmann equation. In the presence of β-BuTX the voltage-dependent activation was shifted towards more negative potentials. 2B: Effect of indomethacin and β-BuTX on voltage-dependence by current/voltage-relationships: relative currents were plotted against the membrane potentials; curves were fitted using the Boltzmann equation. Indomethacin reversed the effect of β-BuTX. 2C: Comparison of activation thresholds from the current voltage-relationships: neither β-BuTX nor indomethacin showed any effect on activation threshold. 2D: Comparison of the potentials of maximal current amplitude obtained from current/voltage-relationships. In the presence of β-BuTX the maximal current amplitude was observed at much more negative potentials. 2E: Comparison of potentials of half maximal activation obtained from Boltzmann fits; β-BuTX shifted the voltage-dependent activation towards more negative voltages which was reversed by indomethacin. 2F: Comparison of the slope-factors of current/voltage-relationships obtained from Boltzmann fits; with β-BuTX the curves were much steeper than under control conditions which could be reversed by indomethacin. (*p < 0.05; **p < 0.01; ***p < 0.001).