FIG. 8.
Inactivation of 4-AP- and TEA-sensitive currents. A Conditioning pulses (150-ms duration) were applied before stepping to the test potential at 0 mV (100-ms duration) (voltage protocol shown in lower trace). Currents were recorded following perfusion of 2.5 mM 4-AP followed by a combination of 2.5 mM 4-AP and 25 mM TEA. B The 4-AP-sensitive current and the TEA-sensitive current both show voltage-dependent inactivation, but the 4-AP-sensitive current has faster kinetics than the TEA-sensitive current. C Inactivation of the TEA-sensitive current as a function of prepulse potential. Conditioning pulses were 500-ms duration. Inactivation of I4-AP from a different cell is included for comparison (plus symbols). A Boltzmann fit represented by dashed line gave a half-inactivation of −66.4 mV and S value of 10.5 mV.