Theoretically, a recognized member of the modern state system possessing formal sovereignty and occupied by a people who see themselves as a single, united nation. Most nations and states aspire to parlance, nation-state is used as a synonym for country or state.
In biology, depolarization is a decrease in the absolute value of a cell's membrane potential. Thus, changes in membrane voltage in which the membrane potential becomes less positive or less negative are both depolarizations.
depolarizing currents established by the influx of Na+ flow down the axon and trigger an action potential at the next segment. The Na+ diffusing into the axon during the first phase of the action potential creates a depolarizing current that brings the next segment, or node, of the axon to threshold.