It prevents the release of ACh by presynaptic cells. It prevents the removal of dopamine from the synaptic cleft. An action potential is brought about by a sudden membrane impermiability the movement of negatively-charged proteins throught the plasma membrane. Multiple sclerosis is caused by a common soil bacteria and can be prevented by vaccination. Many axons make up a nerve.
Many nerves make up an axon.
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.