Why the flow of signals in a synapse is from axonal end of one neuron to dendrite end of another neuron but not the reverse ?
As the electrical impulse reaches the axon terminal in the region of axon-dendrite synapse, it stimulates the exocytosis of vesicles containing
neurotransmitter (e.g. acetylcholine). Neurotransmitter attaches to the chemoreceptor sites of the membrane covering the dendrite end of
synapse. It creates a new impulse that travels through cell body and axon of the second neuron. At synapse, the axon end does not contain any
chemoreceptor sites so that reverse flow of electrochemical impulses is not possible.