What term describes the state when the membrane reaches its resting potential after depolarization?

The term that describes the state when the membrane reaches its resting potential after depolarization is repolarization. This process occurs after a neuron has been stimulated and depolarizes, which involves the membrane potential becoming more positive due to the influx of sodium ions. Following this depolarization, repolarization occurs as potassium ions flow out of the neuron, restoring the negative charge inside the cell relative to the outside.

During repolarization, the membrane potential moves back toward its resting level, which is typically around -70 mV for many neurons. This phase is critical for the recovery and preparation of the neuron for subsequent action potentials. The movements of ions that contribute to repolarization play a vital role in the action potential cycle, allowing for the efficient transmission of signals along the neuron.

Other options refer to different aspects of neuronal activity. Hyperpolarization occurs when the membrane potential becomes even more negative than the resting potential, moving away from the threshold for generating an action potential. Threshold potential refers to the critical level to which a membrane must be depolarized in order to initiate an action potential. Sustained depolarization suggests a prolonged increase in membrane potential that does not return to resting levels.