Negative-shift activation, current reduction and resurgent currents induced by β-toxins from Centruroides scorpions in sodium channels

► A new scorpion β-toxin (Cn8) specific for sodium channels (Nav) is described. ► Effects of Cn8 and three other β-toxins on seven Nav1 sub-types are reported. ► The isoforms more affected for the scorpion β-toxins are Nav1.6, Nav1.1 and Nav1.2. ► The β-toxins can induce “resurgent currents” in isoforms different from Nav1.6. ► Possible functional differences were analyzed by 3D models of the four β-toxins.