Development of serotonergic neurons and their projections.

Neurons producing serotonin are among the earliest to be born in the developing central nervous system. These cells are largely restricted to the hindbrain, where there form primarily in ventral regions. This review describes some of the mechanisms that regulate patterning and differentiation of the embryonic brain, which are implicated in neurogenesis of serotonergic neurons. It also covers the development of serotonergic axon pathways and the potential role of serotonin in regulating developmental processes.