Melatonin-

     The pineal gland hormone and retinal neuromodulator, melatonin, is still not understood in its regulation of the biological clock through the melatonin G-protein coupled receptors. We have continued to work on the molecular regulation of the biosynthetic enzymatic indoleamines, arylalkylamine N-acetyltransferase (AANAT) and hydroxyindole-O-methyltransferase (Craft and Zhan-Poe, 2000).