Orexin

Federal government websites often end in, orexin. The site is secure. Orexin improvements coming to the PMC website in October

Federal government websites often end in. The site is secure. Preview improvements coming to the PMC website in October Learn More or Try it out now. The hypocretins orexins are recently described hypothalamic neuropeptides thought to have an important role in the regulation of sleep and arousal states 1.

Orexin

Thank you for visiting nature. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. Humans and animals lacking orexin neurons exhibit daytime sleepiness, sleep attacks, and state instability. While the circuit basis by which orexin neurons contribute to consolidated wakefulness remains unclear, existing models posit that orexin neurons provide their wake-stabilizing influence by exerting excitatory tone on other brain arousal nodes. Here we show using in vivo optogenetics, in vitro optogenetic-based circuit mapping, and single-cell transcriptomics that orexin neurons also contribute to arousal maintenance through indirect inhibition of sleep-promoting neurons of the ventrolateral preoptic nucleus. Activation of this subcortical circuit rapidly drives wakefulness from sleep by differentially modulating the activity of ventrolateral preoptic neurons. We further identify and characterize a feedforward circuit through which orexin and co-released glutamate acts to indirectly target and inhibit sleep-promoting ventrolateral preoptic neurons to produce arousal. This revealed circuitry provides an alternate framework for understanding how orexin neurons contribute to the maintenance of consolidated wakefulness and stabilize behavioral state. Uma R. Mohan, Honghui Zhang, … Joshua Jacobs. Matthias Ollivier, Joselyn S.

The role of benzodiazepines in the treatment of insomnia: meta-analysis orexin benzodiazepine use in the treatment of insomnia. In the remaining 4 the hypocretin levels were below the control range, orexin.

Orexin neurons receive a variety of signals related to environmental, physiological and emotional stimuli, and project broadly to the entire CNS. Furthermore, a dysfunction of orexinergic system may underlie different pathological conditions. A selective loss orexin neurons was found in narcolepsia, supporting the crucial role of orexins in maintaining wakefulness. In animal models, orexin deficiency lead to obesity even if the consume of calories is lower than wildtype counterpart. Reduced physical activity appears the main cause of weight gain in these models resulting in energy imbalance. Interestingly, orexinergic neurons show connections to regions involved in cognition and mood regulation, including hippocampus. Orexins enhance hippocampal neurogenesis and improve spatial learning and memory abilities, and mood.

Federal government websites often end in. The site is secure. Preview improvements coming to the PMC website in October Learn More or Try it out now. Orexins, also known as hypocretins, are two neuropeptides secreted from orexin-containing neurons, mainly in the lateral hypothalamus LH.

Orexin

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. There are 50,—80, orexin-producing neurons in the human brain, [8] located predominantly in the perifornical area and lateral hypothalamus. Orexin was discovered in almost simultaneously by two independent groups of researchers working on the rat brain. Luis de Lecea, Thomas Kilduff , and colleagues reported the discovery of the hypocretin system at the same time as Takeshi Sakurai from Masashi Yanagisawa 's lab at the University of Texas Southwestern Medical Center at Dallas reported the discovery of the orexins to reflect the orexigenic appetite-stimulating activity of these peptides.

Cartoon dog outline

Reprints and permissions. Annual Review of Pharmacology and Toxicology. Journal of Neurophysiology. Neuroscience , 11—20 Nakamachi, T. Steiner, M. Xiao, F. Data availability The data generated in this study are presented within this paper or its supplementary materials as well as source data are provided with this paper. Neuropsychopharmacology 38 , — Early in , Nishino and co-workers found that the OA concentration in cerebrospinal fluid CSF was abnormally low in seven of nine people with narcolepsy, implying that orexin transmission was deficient in these patients Nishino et al. Neuroscience , 18—23 Anterior thalamic paraventricular nucleus is involved in intermittent access ethanol drinking: role of orexin receptor 2.

.

Depression is a mental illness whose incidence is increasing around the world. The hypocretins: hypothalamus-specific peptides with neuroexcitatory activity. Responses to corticotropin-releasing hormone in the hypercorticolism of depression and Cushing's disease. Hypothalamic orexin stimulates feeding-associated glucose utilization in skeletal muscle via sympathetic nervous system. Rainero, I. Published : 10 October However, the function of orexins in metabolism pathways are far to be completely understood. Harada et al. In contrast, the strong anorectic factor leptin robustly inhibited orexin neurons, causing hyperpolarization and decreasing the firing rate Yamanaka et al. Promotion of sleep by targeting the orexin system in rats, dogs and humans.