Since exocytosis describes the release of neurotransmitters from vesicles with the help of enzymes during synaptic transmission, it is understandable that the following three things affect the rate of exocytosis: 1.) The rate of production of neurotransmitters, 2.) The rate of production of vesicles, and 3.) The activity of the neuron (i.e., the frequency of action potentials). Normally, the axon terminal contains enough neurotransmitters and vesicles to prepare itself for an action potential. These neurotransmitters and vesicles are produced in the cell body with the help of enzymes and transported to the axon terminal.