Figure 3. The gain of the stationary I–f curve decreased when the artificial AHP conductance was increased.

A, I–f curves in control condition ($G_{\text{dc}}^{\max }$ = 0 μS, •), when $G_{\text{dc}}^{\max }$ = 0.5 μS (□) and $G_{\text{dc}}^{\max }$ = 0.9 μS (▴). The decay time constant of the artificial AHP was 23 ms. Data points correspond to the mean stationary discharge frequency for a given current intensity, and the vertical bars show the standard deviation. The oblique lines are the best linear fits of the I–f curves, computed using the least squares method. B, inverse of the stationary gain plotted against the artificial conductance $G_{\text{dc}}^{\max }$ for three values of the AHP decay time constant: 23 ms (▪), 40 ms (○) and 80 ms (⋄). Note that the control gain ($G_{\text{dc}}^{\max }$ = 0 μS) fluctuated from one determination to the other. The oblique lines are the best linear fits. Same motoneurone as in Fig. 2.