Figure 4. Plotted features obtained from S1 L5 pyramidal neurons through voltage recordings in naïve conditions () or under the presence of the TRPM8 channel blocker BCTC 15 μM ().

The extracted features are obtained from different types of stimulation protocols performed on control (black) and under the effect of menthol 250 μM (red). Firing pattern features from successive incremental current square pulses are plotted and compared (A). Last AP analysis (A1) shows little or no difference on the effect produced by menthol 250 μM (red), whether if it is measured in the absence (; n = 9) or in the presence of BCTC 15 μM (; n = 8) (average ± S.E.). A similar situation can be observed in the AP drop rate slope measured (A2; average ± S.E.; *p < 0.05, ***p < 0.005, estimated by Student's t test). Parameters obtained from incremental current ramp stimulation are plotted (B). The effect produced by menthol 250 μM (red) on the threshold (B, left) was not blocked by BCTC 15 μM (; n = 8 Average ± S.E. * p < 0.05, estimated by Student's t test). On the action potential amplitude drop rate (B, right) the effect of menthol 250 μM (red) can be observed in naïve conditions (; n = 9) but stops being statistically significant in the presence of BCTC 15 μM (; n = 8) (average ± S.E.; *** p< 0.005, estimated by Student's t test). The parameters that describe the action potential wave-form are plotted (C) and compared. The lack of effect produced by menthol (red) on the AP amplitude (left) and on the width (right) persists in naïve conditions (; n = 9) and in the presence of BCTC (; n = 8; Average ± S.E.; estimated by Student's t test). However, the blocker seems to have some effect on the width. The input resistance values were extracted from I/V analysis and plotted (D) for voltage at peak (left) and at steady state (right). For each case the resistance appears to remain invariant for all conditions (estimated by Student's t test).