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Orexins
Orexin (), also known as hypocretin, is a neuropeptide that regulates arousal, wakefulness, and appetite. 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.Stanford Center for NarcolepsFAQ(retrieved 27-Mar-2012) It exists in the forms of Orexin-A and Orexin-B. There are 50,000–80,000 orexin-producing neurons in the human brain, located predominantly in the perifornical area and lateral hypothalamus. They project widely throughout the central nervous system, regulating wakefulness, feeding, and other behaviours. There are two types of orexin peptide and two types of orexin receptor. Orexin was discovered in 1998 almost simultaneously by two independent groups of researchers working on the rat brain. One group named it orexin, from ''orexis,'' meaning "appetite" in Greek; the other group named it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orexin-B
Orexin (), also known as hypocretin, is a neuropeptide that regulates arousal, wakefulness, and appetite. 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.Stanford Center for NarcolepsFAQ(retrieved 27-Mar-2012) It exists in the forms of Orexin-A and Orexin-B. There are 50,000–80,000 orexin-producing neurons in the human brain, located predominantly in the perifornical area and lateral hypothalamus. They project widely throughout the central nervous system, regulating wakefulness, feeding, and other behaviours. There are two types of orexin peptide and two types of orexin receptor. Orexin was discovered in 1998 almost simultaneously by two independent groups of researchers working on the rat brain. One group named it orexin, from ''orexis,'' meaning "appetite" in Greek; the other group named it hypo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orexin-B
Orexin (), also known as hypocretin, is a neuropeptide that regulates arousal, wakefulness, and appetite. 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.Stanford Center for NarcolepsFAQ(retrieved 27-Mar-2012) It exists in the forms of Orexin-A and Orexin-B. There are 50,000–80,000 orexin-producing neurons in the human brain, located predominantly in the perifornical area and lateral hypothalamus. They project widely throughout the central nervous system, regulating wakefulness, feeding, and other behaviours. There are two types of orexin peptide and two types of orexin receptor. Orexin was discovered in 1998 almost simultaneously by two independent groups of researchers working on the rat brain. One group named it orexin, from ''orexis,'' meaning "appetite" in Greek; the other group named it hypo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narcolepsy
Narcolepsy is a long-term neurological disorder that involves a decreased ability to regulate sleep–wake cycles. Symptoms often include periods of excessive daytime sleepiness and brief involuntary sleep episodes. About 70% of those affected also experience episodes of sudden loss of muscle strength, known as cataplexy. Narcolepsy paired with cataplexy is evidenced to be an autoimmune disorder. These experiences of cataplexy can be brought on by strong emotions. Less commonly, there may be vivid hallucinations or an inability to move (sleep paralysis) while falling asleep or waking up. People with narcolepsy tend to sleep about the same number of hours per day as people without, but the quality of sleep tends to be lessened. Narcolepsy is a clinical syndrome of hypothalamic disorder, however, the exact cause of narcolepsy is unknown, with potentially several causes. In up to 10% of cases, there is a family history of the disorder. Often, those affected have low levels of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orexin-A
Orexin-A, also known as hypocretin-1, is a naturally occurring neuropeptide and orexin isoform. The orexinergic nucleus in the lateral hypothalamus is the primary orexin projection system in the brain. Structure Orexin-A is a peptide composed of 33 amino acids including an N-terminal pyroglutamyl residue and two intramolecular disulfide bridges between cysteine residues in 6 and 12 and 7 and 14 positions. The amino acid sequence is: Pyroglu-Pro-Leu-Pro-Asp-Cys-Cys-Arg-Gln-Lys-Thr-Cys-Ser-Cys-Arg-Leu-Tyr-Glu-Leu-Leu-His-Gly-Ala-Gly-Asn-His-Ala-Ala-Gly-Ile-Leu-Thr-Leu. Mechanism Orexins are highly excitatory neuropeptides that were first discovered in the brains of rats. It is a peptide that is produced by a very small population of cells in the lateral and posterior hypothalamus. Orexins strongly excite various brain nuclei (neurons) to affect an organism's wakefulness by affecting their dopamine, norepinephrine, histamine and acetylcholine systems. These systems work together to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wakefulness
Wakefulness is a daily recurring Human brain, brain state and state of consciousness in which an individual is conscious and engages in coherent cognition, cognitive and behavioral responses to the external world. Being awake is the opposite of being asleep, in which most external inputs to the brain are excluded from neural processing. Effects upon the brain The longer the brain has been awake, the greater the synchronous firing rates of cerebral cortex neurons. After sustained periods of sleep, both the speed and synchronicity of the neurons firing are shown to decrease. Another effect of wakefulness is the reduction of glycogen held in the astrocytes, which supply energy to the neurons. Studies have shown that one of sleep's underlying functions is to replenish this glycogen energy source. Maintenance by the brain Wakefulness is produced by a complex interaction between multiple neurotransmitter systems arising in the brainstem and ascending through the midbrain, hypothalam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orexin-A
Orexin-A, also known as hypocretin-1, is a naturally occurring neuropeptide and orexin isoform. The orexinergic nucleus in the lateral hypothalamus is the primary orexin projection system in the brain. Structure Orexin-A is a peptide composed of 33 amino acids including an N-terminal pyroglutamyl residue and two intramolecular disulfide bridges between cysteine residues in 6 and 12 and 7 and 14 positions. The amino acid sequence is: Pyroglu-Pro-Leu-Pro-Asp-Cys-Cys-Arg-Gln-Lys-Thr-Cys-Ser-Cys-Arg-Leu-Tyr-Glu-Leu-Leu-His-Gly-Ala-Gly-Asn-His-Ala-Ala-Gly-Ile-Leu-Thr-Leu. Mechanism Orexins are highly excitatory neuropeptides that were first discovered in the brains of rats. It is a peptide that is produced by a very small population of cells in the lateral and posterior hypothalamus. Orexins strongly excite various brain nuclei (neurons) to affect an organism's wakefulness by affecting their dopamine, norepinephrine, histamine and acetylcholine systems. These systems work together to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Hypothalamus
The lateral hypothalamus (LH), also called the lateral hypothalamic area (LHA), contains the primary orexinergic nucleus within the hypothalamus that widely projects throughout the nervous system; this system of neurons mediates an array of cognitive and physical processes, such as promoting feeding behavior and arousal, reducing pain perception, and regulating body temperature, digestive functions, and blood pressure, among many others. Clinically significant disorders that involve dysfunctions of the orexinergic projection system include narcolepsy, motility disorders or functional gastrointestinal disorders involving visceral hypersensitivity (e.g., irritable bowel syndrome), and eating disorders. The neurotransmitter glutamate and the endocannabinoids (e.g., anandamide) and the orexin neuropeptides orexin-A and orexin-B are the primary signaling neurochemicals in orexin neurons; pathway-specific neurochemicals include GABA, melanin-concentrating hormone, nociceptin, glucos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Data Bank
The Protein Data Bank (PDB) is a database for the three-dimensional structural data of large biological molecules, such as proteins and nucleic acids. The data, typically obtained by X-ray crystallography, NMR spectroscopy, or, increasingly, cryo-electron microscopy, and submitted by biologists and biochemists from around the world, are freely accessible on the Internet via the websites of its member organisations (PDBe, PDBj, RCSB, and BMRB). The PDB is overseen by an organization called the Worldwide Protein Data Bank, wwPDB. The PDB is a key in areas of structural biology, such as structural genomics. Most major scientific journals and some funding agencies now require scientists to submit their structure data to the PDB. Many other databases use protein structures deposited in the PDB. For example, SCOP and CATH classify protein structures, while PDBsum provides a graphic overview of PDB entries using information from other sources, such as Gene ontology. History Two force ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incretin
Incretins are a group of metabolic hormones that stimulate a decrease in blood glucose levels. Incretins are released after eating and augment the secretion of insulin released from pancreatic beta cells of the islets of Langerhans by a blood-glucose–dependent mechanism. Some incretins (GLP-1) also inhibit glucagon release from the alpha cells of the islets of Langerhans. In addition, they slow the rate of absorption of nutrients into the blood stream by reducing gastric emptying and may directly reduce food intake. The two main candidate molecules that fulfill criteria for an incretin are the intestinal peptides glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP, also known as: glucose-dependent insulinotropic polypeptide). Both GLP-1 and GIP are rapidly inactivated by the enzyme dipeptidyl peptidase-4 (DPP-4). Both GLP-1 and GIP are members of the glucagon peptide superfamily. Medical uses Medications based on incretins are used in the treatment of diabe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orphan Receptor
In biochemistry, an orphan receptor is a protein that has a similar structure to other identified receptors but whose endogenous ligand has not yet been identified. If a ligand for an orphan receptor is later discovered, the receptor is referred to as an "adopted orphan". Conversely, the term orphan ligand refers to a biological ligand whose cognate receptor has not yet been identified. Examples Examples of orphan receptors are found in the G protein-coupled receptor (GPCR) and nuclear receptor families. If an endogenous ligand is found, the orphan receptor is "adopted" or "de-orphanized". An example is the nuclear receptor Farnesoid X receptor (FXR) and the GPCR TGR5/GPCR19/G protein-coupled bile acid receptor, both of which are activated by bile acids. Adopted orphan receptors in the nuclear receptor group include FXR, liver X receptor (LXR), and peroxisome proliferator-activated receptor (PPAR). Another example of an orphan receptor site is the PCP binding site in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GenBank
The GenBank sequence database is an open access, annotated collection of all publicly available nucleotide sequences and their protein translations. It is produced and maintained by the National Center for Biotechnology Information (NCBI; a part of the National Institutes of Health in the United States) as part of the International Nucleotide Sequence Database Collaboration (INSDC). GenBank and its collaborators receive sequences produced in laboratories throughout the world from more than 500,000 formally described species. The database started in 1982 by Walter Goad and Los Alamos National Laboratory. GenBank has become an important database for research in biological fields and has grown in recent years at an exponential rate by doubling roughly every 18 months. Release 250.0, published in June 2022, contained over 17 trillion nucleotide bases in more than 2,45 billion sequences. GenBank is built by direct submissions from individual laboratories, as well as from bulk submis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union Of Basic And Clinical Pharmacology
The International Union of Basic and Clinical Pharmacology (IUPHAR) is a voluntary, non-profit association representing the interests of scientists in pharmacology-related fields to facilitate ''Better Medicines through Global Education and Research'' around the world. History Established in 1959 as a section of the International Union of Physiological Sciences, IUPHAR became an independent organization in 1966 and is a member of the International Council for Science (ICSU). The first World Congress of Pharmacology was held in Stockholm, Sweden in 1961 and subsequently held every three years. After 1990 the World Congresses were moved to a four-year interval. These meetings present the latest pharmacological research, technology, and methodology, and provide a forum for international collaboration and exchange of ideas. A General Assembly, consisting of delegates from all the member societies, is convened during the congresses so member societies have an opportunity to elect th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
