Which of the following correctly describes hyperpolarization?

Hyperpolarization refers to a change in a neuron’s membrane potential that makes the inside of the cell more negative compared to its resting potential. This typically occurs when potassium ions (K+) exit the neuron or when chloride ions (Cl-) enter, resulting in the membrane potential moving further away from the threshold needed for an action potential. The heightened negativity inside the neuron makes it less likely to fire an action potential, thereby playing a crucial role in the regulation of neuronal excitability.

The other options provided do not accurately describe hyperpolarization. An increase in sodium ion permeability would generally lead to depolarization, while a decrease in potassium ion permeability would maintain or possibly decrease hyperpolarization. Restoration of resting potential occurs after depolarization and repolarization phases of an action potential but does not specifically characterize hyperpolarization itself. Thus, increasing negativity within the neuron accurately defines the hyperpolarization process.