Discovery of the Hypocretins/Orexins and Their Receptors -- The Discovery of the Hypocretins -- Orexin and Orexin Receptors -- Animal Models in the Study of the Hypocretinergic System -- Rodent Models of Human Narcolepsy-cataplexy -- The Canine Model of Narcolepsy -- Detailed Anatomy of the Hypocretinergic System and Related Hypothalamic Circuits -- Anatomy of the Hypocretin System -- The Anatomy of Hypocretin Neurons -- Transmitter-Identified Neurons and Afferent Innervation of the Lateral Hypothalamic Area -- Physiological Consequences of Hypocretin Activation -- Physiological Characteristics of Hypocretin/Orexin Neurons -- The Ne System as a Target for Hypocretin Neurons -- Hypocretin/Orexin Actions on Mesopontine Cholinergic Systems Controling Behavioral State -- The Aminergic Systems and the Hypocretins -- Effects Of Hypocretin/Orexin on the Thalamocortical Activating System -- Pharmacology of the Hypocretins and Drug Design -- In Vivo Pharmacology of Orexin (Hypocretin) Receptors -- Intracellular Signal Pathways Utilized by the Hypocretin/Orexin Receptors -- The Hypocretins in Narcolepsy and Arousal -- The Hypocretins and Narcolepsy -- An Approach to Determining the Functions of Hypocretin (Orexin) -- Hypocretin in Neuropsychiatric Disorders -- Hypocretin/Orexin and Sleep -- Modulation of Cortical Activity and Sleep-Wake States by Hypocretin/Orexin -- The Hypocretins in Feeding and Energy Balance -- Regulation of Hypocretin by Metabolic Signals -- The Hypocretins in Addiction and Hyperarousal -- Hypocretin and Brain Reward Function -- Orexin/Hypocretin and Opioid Dependence -- Dopamine-Hypocretin/Orexin Interactions -- Hypocretin/Orexin in Stress and Arousal -- Role of Hypocretins on Peripheral Systems -- The Hypocretins/Orexins and the Hypothalamo-Pituitary-Adrenal Axis -- Orexins (Hypocretins) in the Gut -- Hypocretins in Endocrine Regulation -- The Hypocretins in Cardiovascular Regulation.

The hypocretins (orexins) are a newly identified (1998) peptide family comprised of two peptides, hypocretin-1 and hypocretin-2. Recent observations suggest an involvement of these peptides, located primarily in the hypothalmus, in the regulation of behavioral state. They are involved in circadian rhythms, metabolism, hormone secretion, body temperature, appetite, cardiovascular functions (e.g., blood pressure), and sleep abnormalities (e.g., narcolepsy and cataplexy).