The direct mechanism for regenerating the resting potential after an action potential

You observe that a neuron treated with a metabolic inhibitor which prevents ATP generation still can generate action potentials even when the cell has little ATP, but the neuron eventually loses the ability You observe that a neuron treated with a metabolic inhibitor which prevents ATP generation still can generate action potentials even when the cell has little ATP, but the neuron eventually loses the ability to generate action potentials. What does this tell you about the direct mechanism for regenerating the resting potential after an action potential?