SEROTONIN: A KEY REGULATOR FOR THE DEVELOPMENT OF BRAIN AND MIND

Abstract

Serotonin is a neurotransmitter of a monoamine group together with dopamine and noradrenalin. In the adult brain, serotonin neurons are located in restricted regions in the brainstem and send axons to widespread brain regions, modulating overall neuronal activities throughout the brain. During the ontogeny, serotonin acts as a developmental regulator. Serotonin neurons are generated early in the fetal brain and animal experiments have revealed that serotonin regulates various aspects of developmental events including neurogenesis (differentiation of neurons), dendritogenesis (elongation and branching of dendrites) and synapse formation. The spatio-temporal regulation of the expression of 14 serotonin receptors underlies the effects of serotonin on different neurons at specific developmental stages. Serotonin system is easily affected by environmental factors such as stress, and alterations in this system in fetal and neonatal brain induce permanent changes in the structure and function of brain. In human, dysregulations of the serotonin functions are closely related to the psychological and mental disorders including depression and anxiety disorder, and alterations in the fetal brain may be the cause of developmental disorder such as autism.