Long-term nerve excitability changes by persistent Na+ current blocker ranolazine

► Threshold tracking can non-invasively provide data on axonal membrane properties. ► Increased persistent Na+ current (Nap) is related to neurodegeneration. ► Threshold tracking monitored the excitability changes by ranolazine, a selective Nap blocker. ► Ranolazine treatment demonstrated a long-term effect on suppression of Nap.