Coined from Greek melas (dark/black) and tonos (tone) because it was discovered through its effect on contracting dark pigment cells in frog skin
A hormone produced by the pineal gland that regulates sleep-wake cycles and circadian rhythms
Coined by Aaron Lerner at Yale University from Greek 'melas' meaning black or dark and '-tonin' from Greek 'tonos' meaning tension or tone. Lerner named it for its ability to lighten skin pigment in frogs by contracting melanin-containing cells (melanophores). The 'mela-' refers to melanin, the dark pigment, and '-tonin' to the toning or contracting effect. Its role in sleep regulation
Melatonin is chemically derived from serotonin in the body — the pineal gland converts serotonin into melatonin when darkness falls. The two words share the -tonin ending because both were named for their toning effects on biological tissue, though they work on completely different systems. One was named for blood vessel tone, the other