Action potentials in neurons require voltage-gated ion channels, specifically voltage-gated sodium (Nav) channels to initiate the rapid depolarization, followed by voltage-gated potassium (Kv) channels that mediate repolarization and afterhyperpolarization. A typical sequence is: Nav channels open in response to depolarization, allowing an inward Na+ current that drives the membrane potential toward the positive range; these channels rapidly inactivate, and Kv channels open with a somewhat slower kinetics to allow K+ efflux, restoring the resting potential. Some neurons also utilize voltage- gated calcium channels in particular contexts, but the canonical fast action potential in most neurons depends on voltage-gated Na+ and K+ channels.