Paxilline inhibits KCa1.1 (BK) channels heterologously expressed in Xenopus oocytes. Left: The effect of 100 nM Paxilline (ab141840) (a), Penitrem A (ab141842) (P-650) (b), and Verruculogen (ab141889) (c) on BK currents. Time course of current amplitude changes upon sequential application of the three toxins. Right: Example of current responses to 100 ms depolarization before (red) and during (black) perfusion of 500 nM Paxilline.