In this paper, we focus on Na v 1.7, for which a recent cryogenic electron microscopy structure is available. We show that Na v 1.7 generate electric fields in the pore that facilitate Na + binding to residues previously associated with selectivity. We demonstrate that these fields are generated while Na v 1.7 is inactivated, and without applied external fields, revealing electrostatic preorganization of the channel. Finally, we show that Na v 1.7 generate eletric fields that promote the vertical motion of the S4 helix, facilitating channel gating.