After an action potential passes, [[1]] (K+) channels open, allowing K+ ions to flow out of the neuron and repolarize the membrane.

After an action potential passes, potassium (K+) channels open, allowing K+ ions to flow out of the neuron and repolarize the membrane.

During an action potential, the opening of voltage-gated sodium (Na+) channels at the initial segment of the axon membrane lead to a rapid influx of Na+ ions into the neuron, causing depolarization of the membrane potential. This depolarization then triggers the opening of voltage-gated potassium channels, which allow K+ ions to flow out of the neuron and repolarize the membrane potential. The efflux of K+ ions also helps to restore the resting membrane potential by hyperpolarizing the neuron.

After the action potential passes, the potassium channels remain open for a brief period of time, allowing additional K+ ions to flow out of the neuron and further repolarize the membrane potential. This period is known as the afterhyperpolarization or refractory period, during which the neuron is less likely to fire another action potential. The opening of the potassium channels also helps to restore the concentration gradients of Na+ and K+ ions that were disrupted during the action potential. This prepares the neuron for the next action potential and ensures that the membrane potential returns to its resting state.