Figure 5.

Conditioning pulse trains reduce the amount of transient and persistent Na⁺ currents at -20 mV in neurons from the preBötC region. Entry into inactivation was determined using a 500 ms prepulse to -20 mV. Inactivation was measured with a 10 ms test pulse to 10 mV after a 20 ms recovery interval at -80 mV (○). The conditioning trains consisted of 15 20 ms pulses separated by 20 ms intervals at -80 mV (•). Insets, Transient Na⁺ current with (•) and without (○) conditioning trains at higher resolution either during beginning of prepulse at -20 mV (left inset) or during test pulse at 10 mV (right inset). The effect of conditioning trains was also studied on persistent Na⁺ current measured at the end of prepulse (middle inset; note different current scale). Note that the conditioning trains and step pulse reduced the amplitude of I_NaT similarly (∼50%). The step pulse similarly reduced I_NaP (∼60%).