It is possible for the release of neurotransmitter into a sy

It is possible for the release of neurotransmitter into a synapse to NOT induce an action potential in the postsynaptic cell

Solution

A neurotransmitter is involved not only in introducing action potential, but it is also directly involved in damping of the nerve potential. It is important to note here that any chemical compound which is released by the nerve endings into the synapse which has a potential to affect the function/trasnmission of information across the neurons can be termed as a neurotransmitter. In this regard, it has been seen that some chemical compounds damp the action potential across the synapse. A classical example of these chemical compounds include vitamin C or ascorbic acid which can function as an inhibitory neurotransitter by preventing uptake of other neurotransmitter across the synapse and thus dampen the traversing bio-chemical information. Another example include gamma amino butyric acid or GABA which dampens the action potential across the synapse by deterioration of ionic concentration of chloride ions.

Thus, neurtrotransmitter can not only excite the action potential, they can also dampen the same to modulate biological functions.