Figure 4

KChIP1 decreases potassium but not calcium current densities. a: Inhibition of potassium currents by KChIP1. Representative recordings from control neurons expressing EGFP alone or KChIP1-EGFP. Potassium current density in KChIP1+ neurons was significantly smaller than that seen in control (*P < 0.01, n = 18). Whole-cell potassium currents were evoked by a voltage step to -15 mV from a holding potential of -75 mV. Steady-state amplitudes were normalized to cell capacitance. b Expression of KChIP1 does not affect Ca²⁺ channels. Representative recordings from control (EGFP+) and KChIP1+ (KChIP1-EGFP) neurons. Ba²⁺ current density in KChIP+ neurons (143.17 ± 11.1 pA/pF, n = 11) was similar to that observed in controls (124.3 ± 8.9 pA/pF, n =12; *P > 0.1). Whole cell Ba²⁺ currents were evoked by a voltage step to 0 mV from a holding potential of -80 mV.