Optimized wave-forms and corresponding current measurements on a full HH model . A. Voltage waveforms parameterized as clamped cubic splines with 4 support points (markers), one optimized to highlight the influence of gKd (black) the other to highlight gNa (grey). B. The trans-membrane current when clamped to the grey input in three conditions: in control (grey), for increased gKd (dashed) and for increased gNa (solid). C. Same as B) but for the black voltage control signal. The regions of interest (grey areas) were optimized to contain data where gNa matters most (B) or gKd matters most (C). The deviation due to upregulation of the respective other parameter is minimal (see insets).