Dorsal root ganglion neurons (DRGs) with projections to the kidneys exhibit predominantly tonic firing patterns, i.e. sustained action potential (AP) firing throughout depolarizing current injection. However, those with non-renal projections answered mostly with a phasic response upon electrical stimulation, i.e. <4 APs upon supra-threshold current injection.With this study we aim to investigate whether a different pattern of voltage-gated sodium channels is underlying this finding in electrical response patterns. DRGs from Th11-L2 were recorded in current clamp mode with the patch clamp technique and characterized as tonic or phasic according to their firing response to supra-threshold current injections. Cells with tonic firing pattern had a lower firing threshold, a lower overshoot and longer action potential duration compared to those with phasic pattern. Following this protocol, single cells were switched to voltage-clamp and potassium and calcium channel blockers were added to the external solution. TTX application then allowed us to characterize the current density and activation kinetics of TTX-sensitive and resistant voltage-gated sodium currents. Tonic cells showed a significantly smaller fraction of TTX-sensitive Na⁺- currents than phasic cells whereas activation did not reveal a significant change between the two groups. In conclusion we found that DRGs with tonic firing patterns are clearly distinguishable from phasic firing cells by their firing threshold, size of overshoot and fraction of TTX-sensitive voltage-gated sodium currents. This suggests that DRGs with renal projections display organ specific firing patterns that might be due to a differential underlying sodium channel expression pattern.