The sequence of shifts in the electrical charge of a neuron is called

An action potential occurs when a neuron sends information down an axon, away from the cell body. Neuroscientists also use the terms, spike or impulse.

An Action Potential takes place in four steps:

Step 1:

Certain chemicals like neurotransmitters bind to dendrites and open special channels called stimulus gated channels.

Step 2:

Here comes depolarization in which neuron undergoes a shift in charge distribution.Charge reaches -59 mV. Positive sodium ions move into the cell and neuron becomes less negative(positive).

Step 3:

Repolarization occurs when the charge reaches a certain limit( 30 mV). Na+ channels stop and K+ channels open resulting in K+ ions moving out of the cell to make the neuron negatively charged again.

Step 4:

Hyperpolarization: K+ ions floods back at such a speed that a charge of -75 mV is reached for a very short period of time before resting potential is reached again.

Here, a neuron is at resting potential when it is not sending messages.

Action potential is the state in which a neuron sends messages down the axon away from the cell body. Action Potential fires when depolarization reaches -55 mV.