Figure 4

Nav1.7/Nav1.8 DKO DRG neurons are deficient in their ability to generate action potentials. a,b) Representative traces of action potentials (upper traces) evoked in response to depolarizing current injections (lower traces) are shown. Wide (a) and narrow (b) action potentials are observed in DKO neurons. c) Illustrates a representative example of graded responses to increasing depolarizing currents in a DKO neuron. d) Same cell as c, holding the neuron at -90 mV prior to depolarizing current injections resulted in generation of an all- or-none like action potential with a fast overshoot. e) Mean resting membrane potential for neurons with wide, narrow and no elicited action potentials (no AP) are shown. f) The bar graph shows the total percentage of neurons capable of firing action potentials in WT, Nav1.7KO and Nav1.7/Nav1.8 knock out mouse DRG neurons. Both DKO and Nav1.7KO groups are different from WT in having percentage of neurons not firing AP (Chi-square test p < 0.001 and p = 0.0072 respectively). Proportion of neurons firing action potentials in DKO or Nav1.7 KO are not significantly different from each other (Chi-square test p = 0.4306).