"How far has science gone in understanding the mechanisms of sleep and wakefulness and the pivotal physiologic and pathologic roles of sleep? Sleep and wakefulness constitute major homeostatic systems, whose proper function is crucial to the health and happiness of the individual. Both systems operate at the intersection of the nervous, endocrine, metabolic and immune systems, and their homeostatic mediators include all kinds of molecules, such as neurotransmitters, neuropeptides, hormones and cytokines. This book succeeds in providing, to large extent, the state-of the-art robust knowledge in this important area of science and medicine." George P. Chrousos, M.D., FAAP, MACP, MACE - University of Athens, Athens, Greece - National Institute of Child, Health and Human Development, National Institutes of Health, Bethesda, MD, USA