Explain the formation of the action potential, it's propagation down the axon, and its contribution to releasing neurotransmitters at the synapse.

An action potential is a short lasting event that follows a consistent trajectory, in which the electrical membrane potential of a cell rapidly rises and falls (Pinel, 2009). Action potentials are located in a section of the axon adjacent to the axon hillock are generated by types of voltage-gated ion channels entrenched in the plasma membrane of a cell, and are a part of the process which occurs during the firing of a neuron. When an action potential fires it sends an electrical signal down the axon to the terminal buttons, which trigger the release of neurotransmitters into synapses (Pinel, 2009). Action potentials either occur to their full potential or do not occur; a principle referred to as the all-or-none law.  

References

Pinel, J.P.J. (2009). Biopsychology (7th ed.). Boston, MA: Allyn and Bacon.