How do neurons make choices about when and when not to fire action potentials and to release neurotransmitters?

when a receptor is stimulated it converts the stimulus energy to action potentials in a neurone which is in contact with it. for example the pacinian corpuscle is a pressure receptor in the dermis of the skin. when pressure is applied the capsule is pressed out of shape deforming the sensory neurone ending inside it causing depolarisation of the membrane.
Neurotransmitters are released into the synaptic cleft from the presynaptic neurone when the presynaptic membrane is depolarised.
stop the stimulus and the action potentials will stop being fired.