Final answer:
Fewer receptors mean that less neurotransmitter is needed for normal stimulations or that the synapse is less sensitive.
Step-by-step explanation:
Fewer receptors mean that less neurotransmitter is needed for normal stimulations or that the synapse is less sensitive. The number of receptors on the postsynaptic membrane determines how many neurotransmitter molecules need to bind to produce a response. If there are fewer receptors, then a smaller amount of neurotransmitter is required to achieve the same level of stimulation.