Sympathetic and parasympathetic postganglionic neurons innervate a wide range of target
tissues. The subpopulation of neurons innervating each target tissue can express unique
combinations of neurotransmitters, neuropeptides, ion channels and receptors, which
together comprise the chemical phenotype of the neurons. The target-specific chemical
phenotype shown by autonomic postganglionic neurons arises during development. In this
review, we examine the different mechanisms that generate such a diversity of neuronal …