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NR2B
Glutamate MDAreceptor subunit epsilon-2, also known as ''N''-methyl D-aspartate receptor subtype 2B (NMDAR2B or NR2B), is a protein that in humans is encoded by the ''GRIN2B'' gene. NMDA receptors ''N''-methyl-D-aspartate (NMDA) receptors are a class of ionotropic glutamate receptors. The NMDA receptor channel has been shown to be involved in long-term potentiation, an activity-dependent increase in the efficiency of synaptic transmission thought to underlie certain kinds of memory and learning. NMDA receptor channels are heterotetramers composed of two molecules of the key receptor subunit NMDAR1 (GRIN1) and two drawn from one or more of the four NMDAR2 subunits: NMDAR2A (GRIN2A), NMDAR2B (GRIN2B), NMDAR2C (GRIN2C), and NMDAR2D (GRIN2D). The NR2 subunit acts as the agonist binding site for glutamate, one of the predominant excitatory neurotransmitter receptors in the mammalian brain. Function NR2B has been associated with age- and visual-experience-dependent plasticity in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NMDA Receptor
The ''N''-methyl-D-aspartate receptor (also known as the NMDA receptor or NMDAR), is a glutamate receptor and ion channel found in neurons. The NMDA receptor is one of three types of ionotropic glutamate receptors, the other two being AMPA receptor, AMPA and kainate receptors. Depending on its subunit composition, its Ligand (biochemistry), ligands are glutamate and glycine (or D-Serine, D-serine). However, the binding of the ligands is typically not sufficient to open the channel as it may be blocked by Magnesium, Mg2+ ions which are only removed when the neuron is sufficiently depolarized. Thus, the channel acts as a “coincidence detector” and only once both of these conditions are met, the channel opens and it allows cation, positively charged ions (cations) to flow through the cell membrane. The NMDA receptor is thought to be very important for controlling synaptic plasticity and mediating learning and memory functions. The NMDA receptor is ionotropic, meaning it is a pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traxoprodil
Traxoprodil (developmental code name CP-101606) is a drug developed by Pfizer which acts as an NMDA antagonist, selective for the NR2B subunit. It has neuroprotective, analgesic, and anti-Parkinsonian effects in animal studies. Traxoprodil has been researched in humans as a potential treatment to lessen the damage to the brain after stroke, but results from clinical trials showed only modest benefit. The drug was found to cause EKG abnormalities (QT prolongation) and its clinical development was stopped. More recent animal studies have suggested traxoprodil may exhibit rapid-acting antidepressant effects similar to those of ketamine, although there is some evidence for similar psychoactive side effects and abuse potential at higher doses, which might limit clinical acceptance of traxoprodil for this application. Traxoprodil showed ketamine-like rapidly-acting antidepressant effects in a small clinical trial of 30 patients with depression who were non-responders to 6 wee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CERC-301
Rislenemdaz (developmental code names CERC-301, MK-0657) is an orally-active, selective NMDA receptor subunit 2B (NR2B) antagonist which is under development by Cerecor in the United States as an adjunctive therapy for treatment-resistant depression (TRD). In November 2013, phase II clinical trials were initiated, and in the same month, rislenemdaz received Fast Track Designation from the Food and Drug Administration for TRD. A pilot study was published in 2012, and a phase II trial was completed in 2014, but was deemed insufficient. A second attempt at a phase II trial in 2016 also found that the drug failed to demonstrate efficacy against depression. Pharmacology Rislenemdaz is a small-molecule antagonist of the NMDA receptor. The NMDA receptor is composed of several subunits, but rislenemdaz is specific for the GluN2B subunits which are only seen in the spinal cord and forebrain. Rislenemdaz binds specifically to the GluN2B subunit in order to prevent endogenous glutamat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rislenemdaz
Rislenemdaz (developmental code names CERC-301, MK-0657) is an orally-active, selective NMDA receptor subunit 2B (NR2B) antagonist which is under development by Cerecor in the United States as an adjunctive therapy for treatment-resistant depression (TRD). In November 2013, phase II clinical trials were initiated, and in the same month, rislenemdaz received Fast Track Designation from the Food and Drug Administration for TRD. A pilot study was published in 2012, and a phase II trial was completed in 2014, but was deemed insufficient. A second attempt at a phase II trial in 2016 also found that the drug failed to demonstrate efficacy against depression. Pharmacology Rislenemdaz is a small-molecule antagonist of the NMDA receptor. The NMDA receptor is composed of several subunits, but rislenemdaz is specific for the GluN2B subunits which are only seen in the spinal cord and forebrain. Rislenemdaz binds specifically to the GluN2B subunit in order to prevent endogenous glutamate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Felbamate
Felbamate (marketed under the brand name Felbatol by MedPointe) is an anticonvulsant used in the treatment of epilepsy. It is used to treat partial seizures (with and without generalization) in adults and partial and generalized seizures associated with Lennox–Gastaut syndrome in children. However, an increased risk of potentially fatal aplastic anemia and/or liver failure limit the drug's usage to severe refractory epilepsy. Mechanism of action Felbamate has been proposed to have a unique dual mechanism of action as a positive modulator of GABAA receptors and as a blocker of NMDA receptors, particularly isoforms containing the NR2B subunit. Although it is clear that felbamate does cause pharmacological inhibition of NMDA receptors, the relevance of NMDA receptor blockade as a strategy for the treatment of human epilepsy has been questioned. Therefore, the importance of the effects of felbamate on NMDA receptors to its therapeutic action in epilepsy is uncertain. Approval hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long-term Potentiation
In neuroscience, long-term potentiation (LTP) is a persistent strengthening of synapses based on recent patterns of activity. These are patterns of synaptic activity that produce a long-lasting increase in signal transmission between two neurons. The opposite of LTP is long-term depression, which produces a long-lasting decrease in synaptic strength. It is one of several phenomena underlying synaptic plasticity, the ability of chemical synapses to change their strength. As memories are thought to be encoded by modification of synaptic strength, LTP is widely considered one of the major cellular mechanisms that underlies learning and memory. LTP was discovered in the rabbit hippocampus by Terje Lømo in 1966 and has remained a popular subject of research since. Many modern LTP studies seek to better understand its basic biology, while others aim to draw a causal link between LTP and behavioral learning. Still, others try to develop methods, pharmacologic or otherwise, of enhanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Besonprodil
Besonprodil (CI-1041) is a drug which acts as an NMDA antagonist, selective for the NR2B subunit. It is under development as a supplemental medication for Parkinson's disease, and has been shown in animals to be effective in counteracting the dyskinesia Dyskinesia refers to a category of movement disorders that are characterized by involuntary muscle movements, including movements similar to tics or chorea and diminished voluntary movements. Dyskinesia can be anything from a slight tremor of ...s associated with long term treatment with levodopa and related drugs. References NMDA receptor antagonists Fluoroarenes Piperidines {{nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eliprodil
Eliprodil (codenamed SL-82.0715) is an NMDA antagonist drug candidate which selectively inhibits the NR2B (GLUN2B) subtype NMDA receptor at submicromolar concentrations. Eliprodil failed a Phase III clinical trial for the treatment of acute ischemic stroke in 1996, sponsored by Synthélabo Recherche.The Pharma Letter. 2 December 199Synthelabo's Eliprodil Fails In Stroke Trials/ref> NMDA receptors are a key component in mediating glutamate-induced excitotoxicity, and it is believed that NMDA antagonists would be neuroprotective after a stroke or other traumatic brain injury. After a traumatic brain injury, neurons become deprived of glucose and oxygen. These neurons quickly lose ATP and become depolarized, which releases glutamate. The extracellular buildup of glutamate triggers the overstimulation of AMPA α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, better known as AMPA, is a compound that is a specific agonist for the AMPA receptor, where it mimics the effects of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive Allosteric Modulator
In pharmacology and biochemistry, allosteric modulators are a group of substances that bind to a receptor to change that receptor's response to stimulus. Some of them, like benzodiazepines, are drugs. The site that an allosteric modulator binds to (i.e., an ''allosteric site'') is not the same one to which an endogenous agonist of the receptor would bind (i.e., an ''orthosteric site''). Modulators and agonists can both be called receptor ligands. Allosteric modulators can be 1 of 3 types either: positive, negative or neutral. Positive types increase the response of the receptor by increasing the probability that an agonist will bind to a receptor (i.e. affinity), increasing its ability to activate the receptor (i.e. efficacy), or both. Negative types decrease the agonist affinity and/or efficacy. Neutral types don't affect agonist activity but can stop other modulators from binding to an allosteric site. Some modulators also work as allosteric agonists. The term "allosteric" derive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAA Receptor
The GABAA receptor (GABAAR) is an ionotropic receptor and ligand-gated ion channel. Its endogenous ligand is γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. Upon opening, the GABAA receptor on the postsynaptic cell is selectively permeable to chloride ions (Cl−) and, to a lesser extent, bicarbonate ions (HCO3−). Depending on the membrane potential and the ionic concentration difference, this can result in ionic fluxes across the pore. If the membrane potential is higher than the equilibrium potential (also known as the reversal potential) for chloride ions, when the receptor is activated Cl− will flow into the cell. This causes an inhibitory effect on neurotransmission by diminishing the chance of a successful action potential occurring at the postsynaptic cell. The reversal potential of the GABAA-mediated inhibitory postsynaptic potential (IPSP) in normal solution is −70 mV, contrasting the GABAB IPSP (-100 mV). T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
