negative regulation of transmission of nerve impulse
positive regulation of transmission of nerve impulse
positive regulation of cytosolic calcium ion concentration
regulation of neurotransmitter secretion
positive regulation of calcium ion transport
phospholipase C-activating G protein-coupled receptor signaling pathway
eating behavior
protein kinase C-activating G protein-coupled receptor signaling pathway
temperature homeostasis
regulation of signaling receptor activity
G protein-coupled receptor signaling pathway
positive regulation of cold-induced thermogenesis
sleep
response to starvation
Sources:Amigo / QuickGO
Orthologs
Species
Human
Mouse
Entrez
3060
15171
Ensembl
ENSG00000161610
ENSMUSG00000045471
UniProt
O43612
O55241
RefSeq (mRNA)
NM_001524
NM_010410
RefSeq (protein)
NP_001515
NP_034540
Location (UCSC)
Chr 17: 42.18 – 42.19 Mb
Chr 11: 100.65 – 100.65 Mb
PubMed search
[3]
[4]
Wikidata
View/Edit Human
View/Edit Mouse
Orexin (/ɒˈrɛksɪn/), also known as hypocretin, is a neuropeptide that regulates arousal, wakefulness, and appetite.[5] It exists in the forms of orexin-A and orexin-B. The most common form of narcolepsy, type 1, in which the individual experiences brief losses of muscle tone ("drop attacks" or cataplexy), is caused by a lack of orexin in the brain due to destruction of the cells that produce it.[6][7]
There are 50,000–80,000 orexin-producing neurons in the human brain,[8] located predominantly in the perifornical area and lateral hypothalamus.[5][9] They project widely throughout the central nervous system, regulating wakefulness, feeding, and other behaviours.[5] There are two types of orexin peptide and two types of orexin receptor.[10][9]
Orexin was discovered in 1998 almost simultaneously by two independent groups of researchers working on the rat brain.[11][12][13] One group named it orexin, from orexis, meaning "appetite" in Greek; the other group named it hypocretin, because it is produced in the hypothalamus and bears a weak resemblance to secretin, another peptide.[6] Officially, hypocretin (HCRT) is used to refer to the genes and transcripts, while orexin is used to refer to the encoded peptides.[14] There is considerable similarity between the orexin system in the rat brain and that in the human brain.[10]
^ abcGRCh38: Ensembl release 89: ENSG00000161610 – Ensembl, May 2017
^ abcGRCm38: Ensembl release 89: ENSMUSG00000045471 – Ensembl, May 2017
^"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ abcDavis JF, Choi DL, Benoit SC (2011). "24. Orexigenic Hypothalamic Peptides Behavior and Feeding - 24.5 Orexin". In Preedy VR, Watson RR, Martin CR (eds.). Handbook of Behavior, Food and Nutrition. Springer. pp. 361–2. ISBN 9780387922713.
^ abStanford Center for Narcolepsy FAQ (retrieved 27-Mar-2012)
^Sutcliffe JG, de Lecea L (October 2000). "The hypocretins: excitatory neuromodulatory peptides for multiple homeostatic systems, including sleep and feeding". Journal of Neuroscience Research. 62 (2): 161–168. doi:10.1002/1097-4547(20001015)62:2<161::AID-JNR1>3.0.CO;2-1. PMID 11020209. S2CID 33215844.
^Scammell TE, Winrow CJ (2011-02-10). "Orexin receptors: pharmacology and therapeutic opportunities". Annual Review of Pharmacology and Toxicology. 51: 243–266. doi:10.1146/annurev-pharmtox-010510-100528. PMC 3058259. PMID 21034217.
^ abMarcus JN, Elmquist JK (2006). "3. Orexin Projections and Localization of Orexin Receptors". In Nishino S, Sakurai T (eds.). The Orexin/Hypocretin System: Physiology and Pathophysiology. Springer. p. 195. ISBN 9781592599509.
^ abBoss C, Roch C (August 2015). "Recent trends in orexin research--2010 to 2015". Bioorganic & Medicinal Chemistry Letters. 25 (15): 2875–2887. doi:10.1016/j.bmcl.2015.05.012. PMID 26045032.
^Sakurai T, Amemiya A, Ishii M, Matsuzaki I, Chemelli RM, Tanaka H, et al. (February 1998). "Orexins and orexin receptors: a family of hypothalamic neuropeptides and G protein-coupled receptors that regulate feeding behavior". Cell. 92 (4): 573–585. doi:10.1016/S0092-8674(00)80949-6. PMID 9491897. S2CID 16294729.
^de Lecea L, Kilduff TS, Peyron C, Gao X, Foye PE, Danielson PE, et al. (January 1998). "The hypocretins: hypothalamus-specific peptides with neuroexcitatory activity". Proceedings of the National Academy of Sciences of the United States of America. 95 (1): 322–327. Bibcode:1998PNAS...95..322D. doi:10.1073/pnas.95.1.322. PMC 18213. PMID 9419374.
^Extance A (2022-11-07). "The brain chemicals that control what we enjoy". chemistryworld.com. Royal Society of Chemistry. Retrieved 2023-04-04.
^Gotter AL, Webber AL, Coleman PJ, Renger JJ, Winrow CJ (July 2012). "International Union of Basic and Clinical Pharmacology. LXXXVI. Orexin receptor function, nomenclature and pharmacology". Pharmacological Reviews. 64 (3): 389–420. doi:10.1124/pr.111.005546. PMID 22759794. S2CID 2038246.
Orexin (/ɒˈrɛksɪn/), also known as hypocretin, is a neuropeptide that regulates arousal, wakefulness, and appetite. It exists in the forms of orexin-A...
An orexin receptor antagonist, or orexin antagonist, is a drug that inhibits the effect of orexin by acting as a receptor antagonist of one (selective...
gene (HCRTR1, HCRTR2). Both orexin receptors exhibit a similar pharmacology – the 2 orexin peptides, orexin-A and orexin-B, bind to both receptors and...
clinically characterized by symptoms of EDS and cataplexy, and/or will have CSF orexin levels of less than 110 pg/ml. Cataplexy are transient episodes of aberrant...
(e.g., anandamide) and the orexin neuropeptides orexin-A and orexin-B are the primary signaling neurochemicals in orexin neurons; pathway-specific neurochemicals...
Suvorexant, sold under the brand name Belsomra, is an orexin antagonist medication which is used in the treatment of insomnia. It is indicated specifically...
Daridorexant, sold under the brand name Quviviq, is an orexin antagonist medication which is used for the treatment of insomnia. Daridorexant is taken...
colocalized on orexin projection neurons in the lateral hypothalamus and many output structures of the orexin system, where the CB1 and orexin receptor 1...
Lemborexant, sold under the brand name Dayvigo, is an orexin antagonist medication which is used in the treatment of insomnia. It is indicated specifically...
neuronal orexin producing cells located in the lateral hypothalamus and a decrease in orexin concentrations in the cerebral spinal fluid. Normally, orexin acts...
hypothalamic neurons that produce the neuropeptide hypocretin (also called orexin), which regulates arousal and has a role in stabilization of the transition...
and associate with arousal. Orexin deficiency has been identified as responsible for narcolepsy. Research suggests that orexin and histamine neurons play...
least some catabolic effects have been discovered, including cytokines, orexin (known as hypocretin), and melatonin.[citation needed] The word catabolism...
homodimers, and they also heterodimerized with both orexin receptors. ... In conclusion, orexin receptors have a significant propensity to make homo-...
an orexin antagonist medication which is under development for the treatment of depression and insomnia. It is a selective antagonist of the orexin OX2...
Danavorexton (developmental code name TAK-925) is a selective orexin 2 receptor agonist. It is a small-molecule compound and is administered intravenously...
"Chapter 6: Widely Projecting Systems: Monoamines, Acetylcholine, and Orexin". In Sydor A, Brown RY (eds.). Molecular Neuropharmacology: A Foundation...
(8–9): 405–11. doi:10.1016/j.mad.2011.06.005. PMC 3367503. PMID 21729715. Orexin receptor antagonists a new class of sleeping pill, National Sleep Foundation...
940) Fluorafinil (CRL-40,941) Fluorenol Methylbisfluoromodafinil Selective orexin receptor agonists (two are currently under development by Takeda, danavorexton...
sensed by glucose-inhibited neurons in the lateral hypothalamus. These orexin-expressing neurons appear to be hyperpolarised (inhibited) by a glucose-activated...
antidepressants and antihistamines, quetiapine, orexin receptor antagonists, and melatonin receptor agonists, the orexin antagonist lemborexant and the Z-drug eszopiclone...
abstract). In specific subregions of each area, either opioid-stimulating or orexin-stimulating microinjections appear to enhance the number of liking reactions...
ramelteon. Dual orexin receptor antagonists are drugs that block the orexin receptors OX1 and OX2, hence reducing the wakeful effect of the orexin system and...
hedonic coldspot. In rats, microinjections of opioids, endocannabinoids, and orexin are capable of enhancing liking reactions in these hotspots. The hedonic...
as a local injection to paralyze facial muscles JNJ-61393215 (JNJ-3215; Orexin-1) – OX1 receptor antagonist Seltorexant (MIN-202, JNJ-42847922, JNJ-922)...
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