Figure 4. Effect of PHT on the development of I_NaP inactivation.

Effect of 100 µM PHT on I_NaP evoked without (leftmost traces) and with inactivating prepulses to −20 mV lasting from 100 ms to 10 seconds in a representative layer V neuron. The arrows indicate the peak current evoked using depolarizing ramp stimuli under control conditions (left) and in the presence of 100 µM PHT (right). Development of I_NaP inactivation in layers II/III (B) and V (C) at −20 mV and in layer V at +40 mV (D) on a semi-logarithmic scale, under control conditions (open triangles) and in the presence of 100 PHT µM (black triangles); the data points were fit to bi-exponential functions with a baseline (see Table 1).