ANTONIETTA MESSINA1,*, VINCENZO MONDA1, ROBERTO AVOLA2, FIORENZO MOSCATELLI3, ANNA A.VALENZANO3, INES VILLANO1, MARIA RUBERTO5, EMANUELE MONDA1, MARCO LA MARRA1, DOMENICO TAFURI4, SERGIO CHIEFFI1, GIUSEPPE CIBELLI1, MARCELLINO MONDA1, GIOVANNI MESSINA1,2
1Department of Experimental Medicine, Section of Human Physiology and Unit of Dietetic and Sport Medicine, Università degli Studi della Campania, Naples, Italy - 2Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy - 3Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy - 4Department of Motor Sciences and Wellness, University of Naples “Parthenope”, Naples, Italy - 5Department of Medical-Surgical and Dental Specialties, Università degli Studi della Campania-Luigi Vanvitelli, Naples, Italy
The orexin-A/hypocretin-1 and orexin-B/hypocretin-2 are neuropeptides synthesized by a cluster of neurons in the lateral hypothalamus. Orexins play an significant role in regulating arousal and attention. The term “arousal” refers to a person’s general state of alertness or excitation, both physiological and psychological. Arousal levels ranges on a continuum from drowsiness through alertness to excitement. Orexin plays an important role in the regulation of feeding behaviour. The orexin stimulates food intake and reduces the metabolic rate, increasing and maintaining the body's energy reserves. Orexins play also a fundamental role in the regulation of the sleep-wake cycle by increasing arousal levels and maintaining wakefulness. Its deficit can cause narcolepsy. Key to the diagnosis of narcolepsy is the combination of a common symptom, excessive daytime sleepiness, and an uncommon symptom, cataplexy, i.e. a sudden and transient episode of muscle weakness
orexin, hypocretin, arousal, attention, sleep, narcolepsy
10.19193/0393-6384_2017_4_096