Serotonin in brain

Serotonin is a neurotransmitter with broad functions in brain development, neuronal activity and behaviors. 

Neurotransmitters are molecules that ferry messages between nerve cells. Serotonin has traditionally been viewed as a modulatory neurotransmitter. It was first demonstrated in the brain central nervous system in 1953.

Through its diverse projections, the serotonin system plays a role in modulating, sleep, appetite, memory/cognitive function, impulsivity, sexual behavior, motor function and affective responsiveness. 

Serotonin is synthesized from the amino acid tryptophan. In the brain, tryptophan is converted to serotonin in a two-step reaction, with each step catalyzed by a different enzyme and then transferred to storage vesicle in neurons.

Serotogenic neurons arise from the raphe nucleus of the brain stem and they project upward to most areas of the brain and downward to peripheral nerve terminals. Raphe nuclei located in the midline of the brain stem.
Serotonin in brain