how to plot sigmoid activation curve for sodium channel

hi matlab community i have a voltage colomn V = [-90.0000 -84.5455 -79.0909 -73.6364 -68.1818 -62.7273 -57.2727 -51.8182 -46.3636 -40.9091 -35.4545 -30.0000 -24.5455 -19.0909 -13.6364 -8.1818 -2.7273 2.7273 8.1818 13.6364 19.0909 24.5455 30.0000 35.4545 40.9091 46.3636 51.8182 57.2727 62.7273 68.1818 73.6364 79.0909 84.5455 90.0000] (mV) and a current colomn I=1.0e+03 *[ -0.0186 -0.0386 -0.0828 -0.2184 -0.6429 -1.7906 -2.4046 -2.3125 -2.0287 -1.6919 -1.4576 -1.2357 -1.0298 -0.8806 -0.7282 -0.6215 -0.5139 -0.4438 -0.3678 -0.2828 -0.1909 -0.0873 0.0044 0.1253 0.2889 0.4730 0.6821 0.9877 1.3166 1.7460 2.3511 3.0306 4.0117 5.1284]

i want to plot I/Imax vs V witch should give a sigmoid curve, but unfortunately it does not. does anyone have some experience in electrophysiology with matlab could help.

Answer 1

[David Goodmanson]

Hello best16, I am certainly no expert but I believe it's the conductance that has a sigmoid curve vs. voltage. A plot of peak current vs. pulse amplitude looks a lot like what you have. See for example http://nerve.bsd.uchicago.edu/med98c.htm , fig. 24.

[best16 programmer]

thank you for your answer,but there is no example referring to how we should plot the activation and inactivation curves