Nav1.8-mediated sodium current recorded on acutely isolated DRG neurons in naïve, PBS-treated and MRMT-1-treated rats.

<p>(A to E): Representative traces of Nav1.8-mediated sodium current in naïve (A), PBS- (B and D) and MRMT-1-treated (C and E) rats, recorded on DRG neurons at 7 (B and C) and 14 (D and E) days after the inoculation of tumor cells or PBS. (F): Statistical analysis of the peak current density. Note that the density of Nav1.8-mediated sodium current is significantly increased in the DRG neurons of bone cancer rats. ^***<i>P</i><0.001, compared to PBS group, two-way ANOVA, n = 17 (MRMT-1) and 16 (PBS). (G): Voltage protocol used for recording Nav1.8-mediated sodium currents with 300 nM TTX in the bath solution. A 500-ms pre-pulse at −40 mV was used to inactivate Nav1.9 sodium channels. (H and I): Activation and inactivation curves of Nav1.8-mediated sodium current in naïve, PBS-treated and MRMT-1-treated rats at 14 days after the inoculation of tumor cells or PBS. Note that no significant alteration is observed either on the activation (H) or on the inactivation (I) curves among the three groups. Activation curves were fitted using the same protocol used for the recording of Nav1.8 sodium current. Note that the curves in Naïve and PBS groups overlap almost completely. The inactivation curves were fitted using the protocol described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114623#s2" target="_blank">methods</a>.