Resting Potential Decay

A neurons' resting membrane potential is maintained because of the differences in the ionic composition and permeability of two essential ions — sodium and potassium.

In the resting state, potassium ions move out through the potassium leak channels, creating an internal negative potential.

To balance the charges, sodium ions enter the cell through sodium leak channels and increase the membrane potential to negative 70 millivolts.

Thus, a cell at rest is like a leaky boat as the ions are being moved in and out of the cell. The sodium-potassium pump moves three sodium ions out and two potassium ions back into the cell to maintain the ionic gradient.

Suppose the sodium-potassium pump fails to function or is inhibited for more than 10 seconds.

The leak channels would continue to move ions until the equilibrium state is reached, where no further net movement of ions occurs.

So, the membrane potential falls or decays to zero in the absence of the gradient. With the loss of the membrane potential, the cell quickly loses its viability.