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Radioligand Assay
A radioligand is a radioactive biochemical substance (in particular, a ligand that is radiolabeled) that is used for diagnosis or for research-oriented study of the receptor systems of the body. In a neuroimaging application the radioligand is injected into the pertinent tissue, or infused into the bloodstream. It binds to its receptor. When the radioactive isotope in the ligand decays it can be measured by positron emission tomography (PET) or single-photon emission computed tomography (SPECT). In ''in vivo'' systems it is often used to quantify the binding of a test molecule to the binding site of a radioligand. The higher the affinity of the molecule the more radioligand is displaced from the binding site and the increasing radioactive decay can be measured by scintillography. This assay is commonly used to calculate the binding constant of molecules to receptors. The transport of the radioligand is described by receptor kinetics. History Radioligands are credited wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha decay ( ), beta decay ( ), and gamma decay ( ), all of which involve emitting one or more particles. The weak force is the mechanism that is responsible for beta decay, while the other two are governed by the electromagnetism and nuclear force. A fourth type of common decay is electron capture, in which an unstable nucleus captures an inner electron from one of the electron shells. The loss of that electron from the shell results in a cascade of electrons dropping down to that lower shell resulting in emission of discrete X-rays from the transitions. A common example is iodine-125 commonly used in medical settings. Radioactive decay is a stochastic (i.e. random) process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper-64
Copper-64 (64Cu) is a positron and beta emitting isotope of copper, with applications for molecular radiotherapy and positron emission tomography. Its unusually long half-life (12.7-hours) for a positron-emitting isotope makes it increasingly useful when attached to various ligands, for PET and PET-CT scanning. Properties 64Cu has a half-life of 12.7 hours and decays 17.9% by positron emission to 64Ni, 39.0% by beta decay to 64Zn, 43.1% by electron capture to 64Ni, and 0.475% gamma radiation/internal conversion. These emissions are 0.579 MeV, 0.653 MeV and 1.35 MeV for beta minus, positron, and gamma respectively. The oxidation states of copper in biology are I and II since Cu3+ is too powerful to exist in biochemical systems. Furthermore, copper(I) exists as a strong complex in aqueous solution and is not often seen. Copper(II) forms mononuclear complexes that are paramagnetic and prefers ligands of sulfur and nitrogen. Copper is essential in the human body as both a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lars H
Lars is a common male name in Scandinavian countries. Origin ''Lars'' means "from the city of Laurentum". Lars is derived from the Latin name Laurentius, which means "from Laurentum" or "crowned with laurel". A homonymous Etruscan name was borne by several Etruscan kings, and later used as a last name by the Roman Lartia family. The etymology of the Etruscan name is unknown. People *Lars (bishop), 13th-century Archbishop of Uppsala, Sweden *Lars Kristian Abrahamsen (1855–1921), Norwegian politician *Lars Ahlfors (1907–1996), Finnish Fields Medal recipient *Lars Amble (1939–2015), Swedish actor and director *Lars Herminius Aquilinus, ancient Roman consul *Lars Bak (born 1980), Danish road bicycle racer *Lars Bak (computer programmer) (born 1965), Danish computer programmer *Lars Bender (born 1989), German footballer *Lars Christensen (1884–1965), Norwegian shipowner, whaling magnate and philanthropist *Lars Magnus Ericsson (1846–1926), Swedish inventor * Lars Eriksson, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT2A Receptor
The 5-HT2A receptor is a subtype of the 5-HT2 receptor that belongs to the serotonin receptor family and is a G protein-coupled receptor (GPCR). The 5-HT2A receptor is a cell surface receptor, but has several intracellular locations. 5-HT is short for 5-hydroxy-tryptamine or serotonin. This is the main excitatory receptor subtype among the GPCRs for serotonin, although 5-HT2A may also have an inhibitory effect on certain areas such as the visual cortex and the orbitofrontal cortex. This receptor was first noted for its importance as a target of serotonergic psychedelic drugs such as LSD and psilocybin mushrooms. Later it came back to prominence because it was also found to be mediating, at least partly, the action of many antipsychotic drugs, especially the atypical ones. Downregulation of post-synaptic 5-HT2A receptor is an adaptive process provoked by chronic administration of selective serotonin reuptake inhibitors (SSRIs) and atypical antipsychotics. Suicidal and otherwis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Setoperone
Setoperone is a compound that is a ligand to the 5-HT2A receptor. It can be radiolabeled with the radioisotope fluorine-18 and used as a radioligand with positron emission tomography (PET). Several research studies have used the radiolabeled setoperone in neuroimaging for the studying neuropsychiatric disorders, such as depression or schizophrenia. Synthesis The starting material is called 6-(2-hydroxyethyl)-7-methyl-2,3-dihydro- ,3hiazolo ,2-ayrimidin-5-oneCID:15586462(1). Halogenation of this with hydrobromic acid in acetic acid giveCID:15586463(2). Sn2 alkylation with 4-(4-fluorobenzoyl)piperidine 6346-57-7(3) under Finkelstein reaction conditions affords setoperone (4). See also * Altanserin * Ketanserin * Pirenperone Pirenperone (, , ; developmental code names R-47456, R-50656) is a serotonin receptor antagonist described as an antipsychotic and tranquilizer which was never marketed. It is a relatively selective antagonist of the serotonin 5-HT2 recepto ... * R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altanserin
Altanserin is a compound that binds to the 5-HT2A receptor (5-Hydroxytryptamine ( serotonin) 2A receptor). Labeled with the isotope fluorine-18 it is used as a radioligand in positron emission tomography (PET) studies of the brain, i.e., studies of the 5-HT2A neuroreceptors. Besides human neuroimaging studies altanserin has also been used in the study of rats. An alternative for PET imaging the 5-HT2A receptor is the [ 11C] volinanserin (MDL-100,907) radioligand. 18F-altanserin and 3H-volinanserin have shown very comparable binding. Both altanserin and MDL 100,907 are 5-HT2A receptor antagonists. 18F.html" ;"title="sup>18F">sup>18Fsetoperone can also be used in PET. An alternative SPECT radioligand is the 123I.html" ;"title="sup>123I">sup>123I 5-I-R91150 receptor antagonist. A rapid chemical synthesis of fluorine-18 and H-2 dual-labeled altanserin has been described. Other ligands for other parts of the serotonin system used in PET studies are, e.g., DASB, ke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapse (journal)
Synapse is a peer-reviewed scientific journal of neuroscience published in New York City by Wiley-Liss to address basic science topics on synaptic function and structure. The editor-in-chief is Benjamin J. Hall ( H. Lundbeck A/S). According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 2.562, ranking it 201st out of 273 journals in the category "Neurosciences". References Wiley-Liss academic journals English-language journals Neuroscience journals Publications established in 1999 {{neuroscience-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT2 Receptor
The 5-HT2 receptors are a subfamily of 5-HT receptors that bind the endogenous neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). The 5-HT2 subfamily consists of three G protein-coupled receptors (GPCRs) which are coupled to Gq/G11 and mediate excitatory neurotransmission Neurotransmission (Latin: ''transmissio'' "passage, crossing" from ''transmittere'' "send, let through") is the process by which signaling molecules called neurotransmitters are released by the axon terminal of a neuron (the presynaptic neuron), ..., including 5-HT2A, 5-HT2B, and 5-HT2C. For more information, please see the respective main articles of the individual subtypes: * 5-HT2A receptor * 5-HT2B receptor * 5-HT2C receptor See also * 5-HT1 receptor * 5-HT3 receptor * 5-HT4 receptor * 5-HT5 receptor * 5-HT6 receptor * 5-HT7 receptor * 5-HT2 antagonists References {{Serotonergics Serotonin receptors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT1A Receptor
The serotonin 1A receptor (or 5-HT1A receptor) is a subtype of serotonin receptor, or 5-HT receptor, that binds serotonin, also known as 5-HT, a neurotransmitter. 5-HT1A is expressed in the brain, spleen, and neonatal kidney. It is a G protein-coupled receptor (GPCR), coupled to the Gi protein, and its activation in the brain mediates hyperpolarisation and reduction of firing rate of the postsynaptic neuron. In humans, the serotonin 1A receptor is encoded by the HTR1A gene. Distribution The 5-HT1A receptor is the most widespread of all the 5-HT receptors. In the central nervous system, 5-HT1A receptors exist in the cerebral cortex, hippocampus, septum, amygdala, and raphe nucleus in high densities, while low amounts also exist in the basal ganglia and thalamus. The 5-HT1A receptors in the raphe nucleus are largely somatodendritic autoreceptors, whereas those in other areas such as the hippocampus are postsynaptic receptors. Function Neuromodulation 5-HT1A recepto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WAY-100635
WAY-100635 is a piperazine drug and research chemical widely used in scientific studies. It was originally believed to act as a selective 5-HT1A receptor antagonist, but subsequent research showed that it also acts as potent full agonist at the D4 receptor. It is sometimes referred to as a silent antagonist at the former receptor. It is closely related to WAY-100135. In light of its only recently discovered dopaminergic activity, conclusions drawn from studies that employed WAY-100635 as a selective 5-HT1A antagonist may need to be re-evaluated. Human PET studies In human PET studies WAY-100635 shows high binding in the cerebral cortex, hippocampus, raphe nucleus and amygdaloid nucleus, while lower in thalamus and basal ganglia. One study described a single case with relatively high binding in the cerebellum. In relating its binding to subject variables one Swedish study found WAY-100635 binding in raphe brain region correlating with self-transcendence and spiritual accep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotransmitter Transporter
Neurotransmitter transporters are a class of membrane transport proteins that span the cellular membranes of neurons. Their primary function is to carry neurotransmitters across these membranes and to direct their further transport to specific intracellular locations. There are more than twenty types of neurotransmitter transporters. Vesicular transporters move neurotransmitters into synaptic vesicles, regulating the concentrations of substances within them. Vesicular transporters rely on a proton gradient created by the hydrolysis of adenosine triphosphate (ATP) in order to carry out their work: v-ATPase hydrolyzes ATP, causing protons to be pumped into the synaptic vesicles and creating a proton gradient. Then the efflux of protons from the vesicle provides the energy to bring the neurotransmitter into the vesicle. Neurotransmitter transporters frequently use electrochemical gradients that exist across cell membranes to carry out their work. For example, some transporters use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroreceptor
A neurotransmitter receptor (also known as a neuroreceptor) is a membrane receptor protein that is activated by a neurotransmitter. Chemicals on the outside of the cell, such as a neurotransmitter, can bump into the cell's membrane, in which there are receptors. If a neurotransmitter bumps into its corresponding receptor, they will bind and can trigger other events to occur inside the cell. Therefore, a membrane receptor is part of the molecular machinery that allows cells to communicate with one another. A neurotransmitter receptor is a class of receptors that specifically binds with neurotransmitters as opposed to other molecules. In postsynaptic cells, neurotransmitter receptors receive signals that trigger an electrical signal, by regulating the activity of ion channels. The influx of ions through ion channels opened due to the binding of neurotransmitters to specific receptors can change the membrane potential of a neuron. This can result in a signal that runs along the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
