Roles of serotonin in the fetal brain

Abstract Serotonin (5-HT) signaling has been linked to both the pathophysiology and treatment of many common psychiatric and neurodevelopmental disorders, including depression, schizophrenia, and autism. Animal models provide growing evidence that perturbation of 5-HT signaling during early brain development is a risk factor for long-lasting behavioral and neuropsychiatric abnormalities. This is consistent with the very diverse modulatory functions that 5-HT signaling exerts in the fetal brain, ranging from neurogenesis and axonal projections and pruning to the regulation of neuronal circuits formation. Moreover, 5-HT ontogenic effects are mediated via a variety of ligand sources, receptors, transporters, and enzymes. In this chapter, we briefly describe this multifaceted system through which epigenetic variations and early adverse experiences can impact fetal brain development. Although years of research have solidified our understanding of the fetal programming of psychiatric disorders, important work remains to be done to fully grasp the extent to which 5-HT function contributes to this process.