FIGURE 4.

N816K mutation enables hyperexcitability in small DRG neurons. (A) Scatter plot of maximal numbers of action potentials evoked by stimuli ranging from 25 to 500 pA in cells expressing WT and N816K mutant hNav1.9 channels. Cells are divided into two groups, those that only fire a single action potential during 500 ms course and those that fire multiple action potentials. N816K mutation increases the proportion of cells that fire multiple action potentials, compared to WT hNav1.9 channels. (B) Average action potential frequency during 500 ms current injections ranging from 25 to 500 pA in 25 pA increments. ^∗p < 0.05.