Orexin/hypocretin research began in 1998, as a result of the discovery of a new hypothalamic neuropeptide. In 1999, it was found that mutations in the orexin/ hypocretin-related genes caused a sleep disorder (narcolepsy) in dogs and mice. These findings were soon followed by the discoveries of orexin/hypocretin ligand deficiency in human narcolepsy. The finding of the major pathophysiological mechanisms of human narcolepsy resulted in its reclassification as a neurological, not a psychiatric, disorder. The - portance of early diagnosis and initiation of treatment for human narcolepsy has been repeatedly emphasized because the disease typically starts around puberty (when social and school influences become important). Orexin/hypocretin de- ciency in narcolepsy subjects can be detected clinically in cerebrospinal fluid (CSF) orexin/hypocretin measures (low CSF orexin/hypocretin levels are strongly asso- ated with narcolepsy-cataplexy among various neurologic and sleep disorders). Thus, the CSF orexin/hypocretin measurements are expected to be included as a diagnostic test for narcolepsy-cataplexy in the second revision of international di- nostic criteria (ICSD). This positive diagnostic test is very useful for establishing an early diagnosis for narcolepsy-cataplexy, and many patients will likely receive im- diate benefits. Cerebrospinal orexin/hypocretin measurements are also informative for the nosological classification of hypersomnia. Because orexin/hypocretin de- ciency is observed in most human narcolepsy-cataplexy, orexin/hypocretin repla- ment therapy is now a promising new choice for the treatment of human narcolepsy, and research in this area is actively in progress.

This volume is intended for neuropharmacologists, psychopharmacologists, pharmacologists, pharmacists, sleep researchers, translational neuroscience researchers, and other basic researchers and clinical scientists interested in an interdisciplinary approach to sleep medicine. The level of the book is aiming at CNS researchers, drug development scientists, basic and clinical sleep researchers, as well as senior medical students and fellows in psychiatry and neurology. Orexin and Sleep provides a unique resource, giving a comprehensive and highly readable summary of the basic concepts in orexin biology and pharmacology along with clinical applications in sleep medicine in general, and narcolepsy in particular.

This volume is intended for neuropharmacologists, psychopharmacologists, pharmacologists, pharmacists, sleep researchers, translational neuroscience researchers, and other basic researchers and clinical scientists interested in an interdisciplinary approach to sleep medicine. The level of the book is aiming at CNS researchers, drug development scientists, basic and clinical sleep researchers, as well as senior medical students and fellows in psychiatry and neurology. Orexin and Sleep provides a unique resource, giving a comprehensive and highly readable summary of the basic concepts in orexin biology and pharmacology along with clinical applications in sleep medicine in general, and narcolepsy in particular.