Serotonin or 5-Hydroxytryptamine

Serotonin or 5-hydroxytryptamine is one of the brain’s significant chemical messengers (neurotransmitters), carrying signals between neurons (nerve cells). Serotonin’s complex biological functions include mood, cognition, reward, learning, memory, and numerous physiological processes. Also see Selective Serotonin Reuptake Inhibitors (SSRIs)