Orexins (hypocretins) have attracted the attention of the scientific community in different pathological mechanisms since their discovery in 1998. Orexin peptides consist of two types, orexin A and B, encoded by the hypocretin neuropeptide precursor gene and then produced from the same precursor, prepro-orexin. Orexin-producing neurones are located in the lateral, dorsomedial, posterior and perifornical regions of the hypothalamus. Orexin A and B signalling is mediated by two G protein-coupled receptors called orexin1 and orexin2 receptors. The signalling of orexin peptides has been investigated in various cells, such as neurons endogenously expressing orexin receptors. The orexin1 receptor is found mainly in regions controlling feeding, learning, memory and reward, whereas the orexin2 receptor is found mainly in regions controlling arousal. From the distribution of orexin neurons and receptors, the orexin system is thought to have multiple functions in physiological mechanisms. Recent evidence suggests that the central orexin system has an important regulatory role for the regulation of food intake and sleep in animal and human models. In addition to its activity in feeding behaviour, orexin also has an active role in energy regulation. Orexin, a hypothalamic neuropeptide that is active in maintaining wakefulness, plays an important role in the regulation of the sleep-wake cycle. Experimental studies with human and animal models in which the effects of orexin system can be analysed in detail may guide therapeutic approaches related to orexin. In this review, the role of orexin in the physiopathological mechanisms of neuropsychiatric disorders such as eating disorders, sleep disorders, addiction, schizophrenia, epilepsy, depression and anxiety is explained.
Cite this Article As : Özen Koca R, Solak Görmüş ZI, Ekenler Ş, Yıldırım B, Akalın M, Simsar B.
Nöropsikiyatrik Hastalıkların Fizyopatolojisinde Oreksin’in Rolü. Mev Med Sci. 2025; 5(1): 22-29
Conflict of interest : The authors declare that they have no conflict of interest.
Mevlana Tıp Bilimleri 2025, Vol5, Issue1 E-ISSN: 2757-976X
Received : , Accepted : , Published Online :
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