Many axons make up a myelin sheath. Many myelin sheaths make up a dendrite. All neurotransmitters have an excitatory effect. Neuromodulators can magnify or reduce the effects of neurotransmitters. All neurotransmitters are reabsorbed intact from the synaptic cleft.
Neurotransmitters diffuse across the plasma membrane of the post-synaptic cell.
Synaptic potentials may vary in magnitude. An action potential continues indefinitely until a quenching signal is released. Neurotransmitter molecules bind to receptors on post-synaptic cells.