What Causes Hyperpolarization?

Hyperpolarization across the cell membrane occurs when potassium ions rush into the cell to repolarize the membrane. The repolarization goes past the resting potential of the membrane and hyperpolarizes the cell lamina.

Cell membranes of nerve cells can conduct electricity in order to propagate action potentials throughout the body. Action potentials occur in response to neurotransmitters in the body. When an action potential occurs, a signal will be sent to a nerve cell to cause the body to undergo an action. Action potentials occur through the actions of depolarization, repolarization and hyperpolarization.

Depolarization occurs whenever the dendrites of a nerve cell receive a stimulus. Sodium channels open and sodium rushes into the cell. Next, the sodium channels close and potassium channels open to repolarize the cell membrane. As potassium channels open, the cell membrane becomes less negative. Finally, potassium channels stay open, and the cell undergoes hyperpolarization.

An action potential is complete whenever the cell has undergone all three of these processes. Once an action potential completes, the cell must return to its resting potential of -70 millivolts. To accomplish this, the sodium potassium pump actively transports sodium ions out of the cell and also actively transports potassium ions into the cell.