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GABAA
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). Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAA Receptor Schematic
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). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcohol (drug)
Alcohol, sometimes referred to by the chemical name ''ethanol'', is a depressant drug that is the active ingredient in drinks such as beer, wine, and distilled spirits (hard liquor). It is one of the oldest and most commonly consumed recreational drugs, causing the characteristic effects of alcohol intoxication ("drunkenness"). Among other effects, alcohol produces happiness and euphoria, decreased anxiety, increased sociability, sedation, impairment of cognitive, memory, motor, and sensory function, and generalized depression of central nervous system (CNS) function. Ethanol is only one of several types of alcohol, but it is the only type of alcohol that is found in alcoholic beverages or commonly used for recreational purposes; other alcohols such as methanol and isopropyl alcohol are significantly more toxic. A mild, brief exposure to isopropanol, being only moderately more toxic than ethanol, is unlikely to cause any serious harm. Methanol, being profoundly more t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscimol
Muscimol (also known as agarin or pantherine) is one of the principal psychoactive constituents of '' Amanita muscaria'' and related species of mushroom. Muscimol is a potent and selective orthosteric agonist for the GABAA receptors and displays sedative-hypnotic, depressant and hallucinogenic psychoactivity. This colorless or white solid is classified as an isoxazole. Muscimol went under clinical trial phase I for epilepsy, but the trial was discontinued. Biochemistry Muscimol is one of the psychoactive compounds responsible for the effects of ''Amanita muscaria'' intoxication. Ibotenic acid, a neurotoxic secondary metabolite of ''Amanita muscaria'', serves as a prodrug to muscimol when the mushroom is ingested or dried, converting to muscimol via decarboxylation. Muscimol is produced in the mushrooms '' Amanita muscaria'' (fly agaric) and ''Amanita pantherina'', along with muscarine (which is present in trace amounts and it is not active), muscazone, and ibote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzodiazepine
Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, insomnia, and seizures. The first benzodiazepine, chlordiazepoxide (Librium), was discovered accidentally by Leo Sternbach in 1955 and was made available in 1960 by Hoffmann–La Roche, who soon followed with diazepam (Valium) in 1963. By 1977, benzodiazepines were the most prescribed medications globally; the introduction of selective serotonin reuptake inhibitors (SSRIs), among other factors, decreased rates of prescription, but they remain frequently used worldwide. Benzodiazepines are depressants that enhance the effect of the neurotransmitter gamma-aminobutyric acid (GABA) at the GABAA receptor, resulting in sedative, hypnotic ( sleep-inducing), anxiolytic (anti-anxiety), anticonvulsant, and muscle relaxant properties. High d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picrotoxin
Picrotoxin, also known as cocculin, is a poisonous crystalline plant compound. It was first isolated by the French pharmacist and chemist Pierre François Guillaume Boullay (1777–1869) in 1812. The name "picrotoxin" is a combination of the Greek words "picros" (bitter) and "toxicon" (poison). A mixture of two different compounds, picrotoxin occurs naturally in the fruit of the '' Anamirta cocculus'' plant, although it can also be synthesized chemically. Due to its interactions with the inhibitory neurotransmitter GABA, picrotoxin acts as a stimulant and convulsant. It mainly impacts the central nervous system, causing seizures and respiratory paralysis in high enough doses. Chemical structure and synthesis Picrotoxin is an equi molar mixture of two compounds, picrotoxinin (C15H16O6; CAS# 17617-45-7) and picrotin (C15H18O7; CAS# 21416-53-5). Of the two compounds, picrotin is less active. Picrotoxin occurs naturally in the fruit of the ''Anamirta cocculus'', a climbing plant f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroactive Steroid
Neurosteroids, also known as neuroactive steroids, are endogenous or exogenous steroids that rapidly alter neuronal excitability through interaction with ligand-gated ion channels and other cell surface receptors. The term ''neurosteroid'' was coined by the French physiologist Étienne-Émile Baulieu and refers to steroids synthesized in the brain. The term, ''neuroactive steroid'' refers to steroids that can be synthesized in the brain, or are synthesized by an endocrine gland, that then reach the brain through the bloodstream and have effects on brain function. The term neuroactive steroids was first coined in 1992 by Steven Paul and Robert Purdy. In addition to their actions on neuronal membrane receptors, some of these steroids may also exert effects on gene expression via nuclear steroid hormone receptors. Neurosteroids have a wide range of potential clinical applications from sedation to treatment of epilepsy and traumatic brain injury. Ganaxolone, a synthetic analog of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotransmitter
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotransmitters are released from synaptic vesicles into the synaptic cleft where they are able to interact with neurotransmitter receptors on the target cell. The neurotransmitter's effect on the target cell is determined by the receptor it binds. Many neurotransmitters are synthesized from simple and plentiful precursors such as amino acids, which are readily available and often require a small number of biosynthetic steps for conversion. Neurotransmitters are essential to the function of complex neural systems. The exact number of unique neurotransmitters in humans is unknown, but more than 100 have been identified. Common neurotransmitters include glutamate, GABA, acetylcholine, glycine and norepinephrine. Mechanism and cycle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbiturate
Barbiturates are a class of depressant drugs that are chemically derived from barbituric acid. They are effective when used medically as anxiolytics, hypnotics, and anticonvulsants, but have physical and psychological addiction potential as well as overdose potential among other possible adverse effects. They have been used recreationally for their anxiolytic and sedative effects, and are thus controlled in most countries due to the risks associated with such use. Barbiturates have largely been replaced by benzodiazepines and nonbenzodiazepines ("Z-drugs") in routine medical practice, particularly in the treatment of anxiety disorders and insomnia, because of the significantly lower risk of overdose, and the lack of an antidote for barbiturate overdose. Despite this, barbiturates are still in use for various purposes: in general anesthesia, epilepsy, treatment of acute migraines or cluster headaches, acute tension headaches, euthanasia, capital punishment, and ass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kavalactones
Kavalactones are a class of lactone compounds found in kava roots and Alpinia zerumbet (Shell ginger). Kavalactones are under research for potential to have various psychotropic effects, including anxiolytic and sedative/ hypnotic activities. Enzyme inhibition Kava extract has been shown in vitro to potentially inhibit a wide range of hepatic enzymes, suggesting a possible potential for interactions with many pharmaceuticals and herbal medications. In human volunteers in vivo inhibition is currently limited to CYP1A2, and CYP2E1 through use of probe drugs to measure inhibition. Research Several preliminary studies are assessing potential effects of kava, including its anxiolytic actions and hepatotoxicity, but the role specifically of kavalactones among many other kava compounds for these effects remains under study. Kavalactone type compounds may help protect against high glucose induced cell damage. Toxicity Several kavalactones (e.g. methysticin and yangonin) affect a gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inhalational Anaesthetic
An inhalational anesthetic is a chemical compound possessing general anesthetic properties that can be delivered via inhalation. They are administered through a face mask, laryngeal mask airway or tracheal tube connected to an anesthetic vaporiser and an anesthetic delivery system. Agents of significant contemporary clinical interest include volatile anesthetic agents such as isoflurane, sevoflurane and desflurane, as well as certain anesthetic gases such as nitrous oxide and xenon. List of inhalational anaesthetic agents Currently-used agents * Desflurane * Isoflurane * Nitrous oxide * Sevoflurane * Xenon Previously-used agents Although some of these are still used in clinical practice and in research, the following anaesthetic agents are primarily of historical interest in developed countries: * Acetylene * Chloroethane (ethyl chloride) * Chloroform * Cryofluorane * Cyclopropane * Diethyl ether * Divinyl ether * Enflurane * Ethylene * Fluroxene * Halothane (still wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaboxadol
Gaboxadol, also known as 4,5,6,7-tetrahydroisoxazolo(5,4-c)pyridin-3-ol (THIP), is a conformationally constrained derivative of the alkaloid muscimol that was first synthesized in 1977 by the Danish chemist Povl Krogsgaard-Larsen. In the early 1980s gaboxadol was the subject of a series of pilot studies that tested its efficacy as an analgesic and anxiolytic, as well as a treatment for tardive dyskinesia, Huntington's disease, Alzheimer's disease, and spasticity. It was not until 1996 that researchers attempted to harness gaboxadol's frequently reported sedative "adverse effect" for the treatment of insomnia, resulting in a series of clinical trials sponsored by Lundbeck and Merck. In March, 2007, Merck and Lundbeck cancelled work on the drug, citing safety concerns and the failure of an efficacy trial. It acts on the GABA system, but in a different way from benzodiazepines, Z-Drugs, and barbiturates. Lundbeck states that gaboxadol also increases deep sleep (stage 4). Unlike b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonbenzodiazepine
Nonbenzodiazepines (), sometimes referred to colloquially as Z-drugs (as many of their names begin with the letter "z"), are a class of psychoactive drugs that are very benzodiazepine-like in nature. They are used in the treatment of sleep problems, and for their anxiolytic effects. Nonbenzodiazepine pharmacodynamics are almost entirely the same as benzodiazepine drugs and therefore exhibit similar benefits, side-effects, and risks. However, nonbenzodiazepines have dissimilar or entirely different chemical structures and are therefore unrelated to benzodiazepines on a molecular level. Classes Currently, the major chemical classes of nonbenzodiazepines are: Imidazopyridines * Alpidem * Necopidem * Saripidem * Zolpidem (Ambien, Ambien CR, Intermezzo, Zolpimist, Edluar, Ivadal, Sanval, Stilnox, etc.) Pyrazolopyrimidines * Divaplon * Fasiplon * Indiplon * Lorediplon * Ocinaplon * Panadiplon * Taniplon * Zaleplon (Sonata, Starnoc, Andante) Cyclopyrrolones * Eszopiclone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
