Differential state-dependent modification of inactivation-deficient Nav1.6 sodium channels by the pyrethroid insecticides S-bioallethrin, tefluthrin and deltamethrin

► We constructed Nav1.6Q3 sodium channels containing the IFM/QQQ mutation. ► Nav1.6Q3 channels expressed in Xenopus oocytes exhibited persistent activation. ► Opening of Nav1.6Q3 channels enhanced modification by tefluthrin and deltamethrin. ► Modification by S-bioallethrin was not affected by channel opening. ► These results provide evidence for differential pyrethroid binding to open channels.