Figure 5. Effects of δ/ω-PLTX-Pt1a on voltage-dependent Na⁺ currents.

Representative whole-cell Na⁺ currents recorded from a cultured Drosophila neuron, before (A) and after the application of 20 nM δ/ω-PLTX-Pt1a (B). Na²⁺ currents were evoked by a series of depolarizing voltage steps in 10 mV increments from a holding potential of −80 mV. (C) To compare the voltage-dependence of Na⁺ channel activation, peak Na⁺ currents before (open circles) and after δ/ω-PLTX-Pt1a (solid circles) were normalized to the maximum amplitude (I/Imax) and plotted against test potentials. (n = 7; mean ± S.E.). D. Representative Na⁺ current traces were normalized and aligned to show a slowing of channel inactivation by δ/ω-PLTX-Pt1a.