ABSTRACT
ABSTRACT When tryptophan is taken up by the body, some is used for the synthesis of serotonin. As well as having neuroregulatory effects, serotonin is also the precursor for the synthesis of N-acetylserotonin (NAS) and melatonin, which form the melatonergic pathways. The melatonergic pathways are associated with many of the changes that are thought to be important in the pathophysiology of Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and major depressive disorder. As well as being produced by the pineal gland at night, and thereby contributing to the circadian rhythm, melatonin is also very highly produced in other organs and tissues, including the gut, where
Introduction ............................................................................................................................................ 423 Melatonergic Pathways Overview ......................................................................................................... 424 Immune-Pineal Axis (IPA) .................................................................................................................... 426 Melatonin and Alzheimer’s Disease ....................................................................................................... 426
Parkinson’s Disease .......................................................................................................................... 428 Multiple Sclerosis .................................................................................................................................. 429 Major Depressive Disorder .................................................................................................................... 430 N-acetylserotonin ................................................................................................................................... 430 Melatonin: Role in Pharmaceutical and Nutritional Interventions .........................................................431
