The document discusses various neurotransmitters, including their structures, biosynthesis, mechanisms of action, and metabolism. It describes catecholamines such as epinephrine, norepinephrine, and dopamine. It also discusses the cholinergic neurotransmitter acetylcholine, the inhibitory neurotransmitter GABA, serotonin, histamine, and the excitatory neurotransmitter glutamate. For each one, it provides details on their chemical structures, how they are synthesized and degraded, and their roles in neurotransmission.