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α5IA
α5IA (LS-193,268) is a nootropic drug invented in 2004 by a team working for Merck, Sharp and Dohme, which acts as a subtype-selective inverse agonist at the benzodiazepine binding site on the GABAA receptor. It binds to α1, α2, α3 and α5 -containing subtypes, with functional selectivity for α5-containing subtypes. Clinical research Administration of α5IA following alcohol consumption was found to reverse memory impairments induced by alcohol. ''In vitro'' electrophysiology Recordings of local field potentials Local field potentials (LFP) are transient electrical signals generated in nerves and other tissues by the summed and synchronous electrical activity of the individual cells (e.g. neurons) in that tissue. LFP are "extracellular" signals, meaning t ... indicate that oral administration of α5IA increases the amplitude of sharp wave ripples which are implicated in memory function in adult wild type rats. The increase in ripple amplitude is not seen i ... [...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 (biochemistry), ligand is γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. Accurate regulation of GABAergic transmission through appropriate developmental processes, specificity to neural cell types, and responsiveness to activity is crucial for the proper functioning of nearly all aspects of the central nervous system (CNS). Upon opening, the GABAA receptor on the Chemical synapse, postsynaptic cell is selectively permeable to Chloride, chloride ions () and, to a lesser extent, Bicarbonate, bicarbonate ions (). GABAAR are members of the ligand-gated ion channel receptor superfamily, which is a chloride channel family with a dozen or more heterotetrametric subtypes and 19 distinct subunits. These subtypes have distinct brain regional and subcellular localization, age-dependent expression, and the ability to undergo plastic alt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAA Receptor Negative Allosteric Modulators
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. Accurate regulation of GABAergic transmission through appropriate developmental processes, specificity to neural cell types, and responsiveness to activity is crucial for the proper functioning of nearly all aspects of the central nervous system (CNS). Upon opening, the GABAA receptor on the postsynaptic cell is selectively permeable to chloride ions () and, to a lesser extent, bicarbonate ions (). GABAAR are members of the ligand-gated ion channel receptor superfamily, which is a chloride channel family with a dozen or more heterotetrametric subtypes and 19 distinct subunits. These subtypes have distinct brain regional and subcellular localization, age-dependent expression, and the ability to undergo plastic alterations in response to experience, including drug exposure. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABRA5
Gamma-aminobutyric acid (GABA) A receptor, alpha 5, also known as GABRA5, is a protein which in humans is encoded by the ''GABRA5'' gene. Function GABA is the major inhibitory neurotransmitter in the mammalian brain where it acts at GABAA receptors, which are ligand-gated chloride channels. Chloride conductance of these channels can be modulated by agents such as benzodiazepines that bind to the GABAA receptor. At least 16 distinct subunits of GABAA receptors have been identified. Transcript variants utilizing three different alternative non-coding first exons have been described. Subunit selective ligands Recent research has produced several ligands which are moderately selective for GABAA receptors containing the α5 subunit. These have proved to be useful in investigating some of the side effects of benzodiazepine and nonbenzodiazepine drugs, particularly the effects on learning and memory such as anterograde amnesia. Inverse agonists at this subunit have nootropic effects and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAA Receptor Negative Allosteric Modulator
A GABAA receptor negative allosteric modulator is a negative allosteric modulator (NAM), or inhibitor, of the GABAA receptor, a ligand-gated ion channel of the major inhibitory neurotransmitter γ-aminobutyric acid (GABA). They are closely related and similar to GABAA receptor antagonists. The effects of GABAA receptor NAMs are functionally the opposite of those of GABAA receptor positive allosteric modulators (PAMs) like the benzodiazepines, barbiturates, and ethanol (alcohol). Non-selective GABAA receptor NAMs can produce a variety of effects including convulsions, neurotoxicity, and anxiety, among others. Selective NAMs (or "inverse agonists") of α5 subunit-containing GABAA receptors, such as basmisanil and α5IA, do not have convulsant or anxiogenic effects but instead show cognitive- and memory-enhancing or nootropic-like effects. They are under investigation for the treatment of cognitive impairment in conditions like Down syndrome and schizophrenia. In addition, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nootropic
Nootropics ( or ) (colloquially brain supplements, smart drugs, cognitive enhancers, memory enhancers, or brain boosters) are chemical substances which purportedly improve cognitive functions, such as attention, memory, wakefulness, and self-control. In the United States, nootropics can be over-the-counter drugs and commonly advertised with unproven claims of effectiveness for improving cognition. The Federal Trade Commission and FDA have warned manufacturers and consumers about possible advertising fraud and marketing scams concerning nootropic supplements. Nootropics include both prescription drugs and dietary supplements marketed to enhance brain function, but while FDA-approved drugs have proven benefits and oversight, many dietary supplements lack evidence, may contain unapproved or hidden drugs, and pose safety and regulatory risks.Nootropics: Drugs vs Dietary Supplements for Brain Health. Operation Supplement Safety. https://www.opss.org/article/nootropics-drugs- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aromatic Ethers
In organic chemistry, aromaticity is a chemical property describing the way in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibits a stabilization stronger than would be expected from conjugation alone. The earliest use of the term was in an article by August Wilhelm Hofmann in 1855. There is no general relationship between aromaticity as a chemical property and the olfactory properties of such compounds. Aromaticity can also be considered a manifestation of cyclic delocalization and of resonance. This is usually considered to be because electrons are free to cycle around circular arrangements of atoms that are alternately single- and double- bonded to one another. This commonly seen model of aromatic rings, namely the idea that benzene was formed from a six-membered carbon ring with alternating single and double bonds (cyclohexatriene), was developed by Kekulé (see History section below). Each bond may be seen as a hybrid of a single bond a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoxazoles
Isoxazole is an electron-rich azole with an oxygen atom next to the nitrogen. It is also the class of compounds containing this ring. Isoxazolyl is the univalent functional group derived from isoxazole. Occurrence Isoxazole rings are found in some natural products, such as ibotenic acid and muscimol. Synthesis Isoxazole can be synthesised via a variety of methods. Examples include via a 1,3-dipolar cycloaddition of nitrile oxides with alkynes; or the reaction of hydroxylamine with 1,3-diketones or derivatives of propiolic acid. Photochemistry The photolysis of isoxazole was first reported in 1966. Due to the weak N-O bond, the isoxazole ring tends to collapse under UV irradiation, rearranging to oxazole through azirine intermediate. Meanwhile, the azirine intermediate can react with nucleophiles, especially carboxylic acids. Given the photoreactions, isoxazole group is developed as a native photo-cross-linker for photoaffinity labeling and chemoproteomic studies. Pharmac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sharp Waves And Ripples
Sharp waves and ripples (SPW-R), also called sharp wave ripples (SWR), are oscillatory patterns produced by extremely synchronized activity of neurons in the mammalian hippocampus and neighboring regions which occur spontaneously in idle waking states or during NREM sleep. They can be observed with a variety of electrophysiological methods such as field recordings or EEG. They are composed of large amplitude sharp waves in local field potential and produced by thousands of neurons firing together within a 30–100 ms window. Within this broad time window, pyramidal cells fire only at specific times set by fast spiking GABAergic interneurons. The fast rhythm of inhibition (150-200 Hz) synchronizes the firing of active pyramidal cells, each of which only fires one or two action potentials exactly between the inhibitory peaks, collectively generating the ripple pattern. SWRs have been extensively characterized by György Buzsáki and have been shown to be involved in memory consolidat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Field Potential
Local field potentials (LFP) are transient electrical signals generated in nerves and other tissues by the summed and synchronous electrical activity of the individual cells (e.g. neurons) in that tissue. LFP are "extracellular" signals, meaning that they are generated by transient imbalances in ion concentrations in the spaces outside the cells, that result from cellular electrical activity. LFP are 'local' because they are recorded by an electrode placed nearby the generating cells. As a result of the Inverse-square law, such electrodes can only 'see' potentials in a spatially limited radius. They are 'potentials' because they are generated by the voltage that results from charge separation in the extracellular space. They are 'field' because those extracellular charge separations essentially create a local electric field. LFP are typically recorded with a high-impedance microelectrode placed in the midst of the population of cells generating it. They can be recorded, for exa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABRA3
Gamma-aminobutyric acid receptor subunit alpha-3 is a protein that in humans is encoded by the ''GABRA3'' gene. Function GABA is the major inhibitory neurotransmitter in the mammalian brain where it acts at GABAA receptors, which are ligand-gated chloride channels. Chloride conductance of these channels can be modulated by agents such as benzodiazepines that bind to the GABAA receptor. At least 16 distinct subunits of GABA-A receptors have been identified. GABA receptors are composed of 5 subunits with an extracellular ligand binding domains and ion channel domains that are integral to the membrane. Ligand binding to these receptors activates the channel. Subunit selective ligands Recent research has produced several ligands that are selective for GABAA receptors containing the α3 subunit. Subtype-selective agonists for α3 produce anxiolytic effects without sedative, amnesia, or ataxia. selective a3 agonists also show lack of dependence, and could make them superior to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merck & Co
Merck & Co., Inc. is an American Multinational corporation, multinational pharmaceutical company headquartered in Rahway, New Jersey. The company does business as Merck Sharp & Dohme or MSD outside the United States and Canada. It is one of the largest pharmaceutical companies in the world, generally ranking in the global top five by revenue. Merck & Co. was originally established as the American affiliate of Merck Group in 1891. Merck develops and produces medicines, vaccines, biologic therapies and animal health products. It has several blockbuster products, including cancer immunotherapy, anti-diabetic medications, and vaccines for HPV and chickenpox, each generating significant revenue as of 2020. The company is ranked 71st on the 2022 Fortune 500, ''Fortune'' 500 and 87th on the 2022 Forbes Global 2000, ''Forbes'' Global 2000, both based on 2021 revenues. In 2023, the company’s seat in the ''Forbes'' Global 2000 was 73. Products The company develops medicines, vaccines, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABRA2
Gamma-aminobutyric acid receptor subunit alpha-2 is a protein in humans that is encoded by the ''GABRA2'' gene. GABRA2 is an alpha subunit that is part of GABAA receptor, GABA-A receptors, which are Ligand-gated ion channel, ligand-gated chloride channels and are activated by the major inhibitory neurotransmitter in the mammalian brain, GABA. Chloride conductance of these channels can be modulated by agents, such as benzodiazepines (psychoactive drugs) that bind to the GABA-A receptor. GABA-A receptors are composed of two alpha, two beta, and one gamma subunits. They have at least 16 distinct subunits identified, including GABRA2. This receptor is found mainly in specific regions of the brain, such as the hippocampus. Subunit isoforms are seen around in various locations in the brain throughout growth. The combination of subunits has a large effect on the pharmacological and biophysical characteristics. GABRA2 has been found to mediate anxiolytic activity, which plays a key role ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
