Answer:
When a neuron fires and its electric charge travels down the axon, causing neurotransmitters to be released by the neuron's terminal buttons, an action potential occurs.
Step-by-step explanation:
An action potential, commonly termed as impulse, can be described as messages which are transferred in electrical form. Action potential are caused due to different electric charges. An action potential is generated by a stimulus which causes transfer of sodium ions into the axons resulting in depolarization of the neuron. To overcome this, potassium ion will enter the cell and an action potential will be generated.
The action potential causes release of the neurotransmitters so that signal messages could be transferred.