Answer:
Receptors for neurotransmitters are mostly found on the postsynaptic membrane
Explanation:
One-way synaptic transmission is usually a chemical synapsis, where an electrical impulse is transmitted along the neuron's axon until it reaches the axon terminals, then a depolarization of the presynaptic membrane occurs, leading to the liberation of neurotransmitter molecules from the synaptic vesicles (located in the presynaptic membrane) into the synaptic cleft. Then the neurotransmitter molecules are captured by specific receptors found in the membrane of the postsynaptic neuron, what then leads to a hyperpolarization of the membrane followed by the generation of the postsynaptic potential.
This process can only occur in one direction because the synaptic vesicles are only found in the axon terminals, while the neurotransmitters receptors are only found on dendrites.