In a neuron, during the depolarization phase that may trigger an action potential . See Concept 48.3 (Page) View Available Hint(s) In a neuron, during the depolarization phase that may trigger an action potential . See Concept 48.3 (Page) most voltage-gated sodium channels become inactivated most voltage-gated sodium channels are open some voltage-gated sodium channels are open most voltage-gated sodium and potassium channels are open most voltage-gated potassium channels are open