Na_v1.8 channel.

<p>(A) Voltage dependence of steady state activation (<i>m</i>_∞) and inactivation (<i>h</i>_∞) of the channel. Squares (=<i>m</i>_∞) and triangles (=<i>h</i>_∞) are the experimental data (Expt.) for bladder small DRG neuron [<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1006293#pcbi.1006293.ref007" target="_blank">7</a>]. Solid (<i>m</i>_∞) and dashed (<i>h</i>_∞) lines represents simulation results (Sim.). (B) The voltage dependence of time constants of activation (<i>τ</i>_<i>m</i>, solid line) and inactivation (<i>τ</i>_<i>h</i>, dashed line). Triangles (=<i>τ</i>_<i>h</i>) are the experimental data (Expt.). (C) <i>Na</i>_<i>v</i>1.8 currents (I_{<i>Na</i>_<i>v</i>1.8}) from simulation (solid lines) using rectangular voltage clamp protocol. The holding potential was kept at −70 mV for 5 ms and the test potentials of 50 ms were applied at −15, 5, 25, 35 and 45 mV. (D) Peak I-V relationships obtained from experiments (squares, [<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1006293#pcbi.1006293.ref007" target="_blank">7</a>]) and simulations (solid line). Protocol: Rectangular voltage clamp from −80 to 45 mV in steps of 10 mV from a holding potential of −60 mV. The peak currents is plotted for each test potential. Other parameters: , E_Na = 38 mV, RMP = −53.5 mV, total capacitance = 28 pF and soma diameter = 24 <i>μ</i>m [<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1006293#pcbi.1006293.ref007" target="_blank">7</a>]. The S values for model fits and their 5% threshold values (given in brackets) are: <i>m</i>_∞ = 0.042 (0.05), <i>h</i>_∞ = 0.033 (0.05), and I-V curve = 0.115 nA (0.203 nA).