Figure 2. Recorded traces of stimuli eliciting AP affected by extracellular menthol 250 μM and corresponding analysis.

Single cell voltage recordings in control conditions (black) and in the presence of menthol 250 μM (red) from S1 somatosensory cortex layer 5 pyramidal neurons. The features extracted were affected by the presence of the AIS. Voltage recordings (A) under pulse stimuli, a set of 11 successive trials of increasing two-second long square current steps. Traces show action potential firing in the control situation (top, black) and under the effects of menthol 250 μM (bottom, red). The action potential amplitude drop rate (B) was obtained from each corresponding current step for both conditions (1) the amplitude drop rates for each condition were averaged and plotted (2) (n = 9 average ± S.E.; p < 0.005 assessed by Student's t-test). Further analysis was performed on the last action potential of each of the 11 trials per condition (C1). These features were plotted against their corresponding trials, for both conditions (C 2) (average ± S.E.; n = 9). Ramp stimuli (D1) was performed providing a measure for the action potential threshold (D2, Top) (p < 0.005; assessed by Student's t-test) and the action potential amplitude drop rate (D2, Bottom) (p < 0.05; assessed by Student's t-test) plotted for both conditions (average ± S.E.; n = 9).