Phenytoin Inhibits the Persistent Sodium Current in Neocortical Neurons by Modifying Its Inactivation Properties
Figure 1
INaP activation and time dependent inactivation.
A, INaP evoked in a representative neuron by means of a slow voltage ramp compared with the current trace evoked in the presence of TTX, revealing a small outward current activating at more positive potentials. B, kinetics of development of INaP time-dependent inactivation assessed with and without TTX subtraction, which completely overlap. The data points are fit with a bi-exponential function. The inset illustrates the stimulus protocol. C, examples of INaP traces with or without TTX subtraction evoked after inactivating prepulses to 0 mV lasting from 100 ms to 10 seconds. The traces are shown partially overlapped to better compare peak amplitude.