What is orexin?

Orexin

Orexin, also called hypocretin, is a neurotransmitter that regulates arousal, wakefulness, and appetite. The most common form of narcolepsy, in which the sufferer briefly loses muscle tone (cataplexy), is caused by a lack of orexin in the brain due to destruction of the cells that produce it.

Read more about Orexin.

Some articles on orexin:

Orexin-A - Ongoing Research
... The test group was administered orexin-A intravenously, or nasally ... The sleep-deprived monkeys, which were given the nasal form of orexin-A, performed far better than the ones treated with injections ... Orexin-A not only restored the monkey’s cognitive abilities but made their brains appear awake in PET scans ...
Wakefulness - Maintenance By The Brain
... Another key system is that provided by the orexins (also known as hypocretins) projecting neurons ... Orexin deficiency has been identified as responsible for narcolepsy ... Research suggests that orexin and histamine neurons play distinct, but complementary roles in controlling wakefulness with orexin being more involved with wakeful behavior ...
Orexin-A - Effects of Supplementation
... To date, orexin-A has shown no negative side effects ... Taking orexin-A also increases arousal, alertness, attention, and muscle tone ... Orexin-A has no effect on subjects who are well rested ...
Orexin - Interaction With Other Neurotransmitter Systems
... Orexins act on Gq-protein-coupled receptors signaling through phospholipase C (PLC) and calcium-dependent as well as calcium-independent transduction pathways ... Postsynaptic actions of orexins on their numerous neuronal targets throughout the CNS are almost entirely excitatory ...
Orexin Receptor
... The orexin receptor (also referred to as the hypocretin receptor) is a G-protein-coupled receptor that binds the neuropeptide hormone orexin ... Both orexin receptors exhibit a similar pharmacology - the 2 orexin peptides, orexin-A and orexin-B, bind to both receptors and, in each case, agonist binding results in ... However, orexin-B shows a 10-fold selectivity for orexin receptor type 2, whilst orexin-A is equipotent at both receptors ...