Transpolarization

Transpolarization (overshoot) is a change in membrane polarity that occurs during action potential. The powerful cationic current flowing into the cell during the depolarization phase of the action potential leads to a short-term reversal of the polarity of the cell membrane - a positive charge prevails near the membrane facing the cell, while a negative charge prevails on the extracellular side of the membrane.

''The area in light blue shows the section of the action potential at which membrane transpolarization occurs. MN = membrane voltage'''