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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] |
GABAB Receptor
GABAB receptors (GABABR) are G protein-coupled receptor, G-protein coupled receptors for gamma-aminobutyric acid (GABA), therefore making them metabotropic receptors, that are linked via G-proteins to potassium channels. The changing potassium concentrations hyperpolarize the cell at the end of an action potential. The reversal potential of the GABAB-mediated IPSP (inhibitory postsynaptic potential) is −100 mV, which is much more hyperpolarized than the GABAA receptor, GABAA IPSP. GABAB receptors are found in the central nervous system and the autonomic nervous system, autonomic division of the peripheral nervous system. The receptors were first named in 1981 when their distribution in the CNS was determined, which was determined by Norman Bowery and his team using radioactively labelled baclofen. Functions GABABRs stimulate the opening of Potassium channel, K+ channels, specifically G protein-coupled inwardly-rectifying potassium channel, GIRKs, which brings the neuro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cicutoxin
Cicutoxin is a naturally-occurring poisonous chemical compound produced by several plants from the family Apiaceae including water hemlock ('' Cicuta'' species) and water dropwort (''Oenanthe crocata''). The compound contains polyene, polyyne, and alcohol functional groups and is a structural isomer of oenanthotoxin, also found in water dropwort. Both of these belong to the C17-polyacetylenes chemical class. It causes death by respiratory paralysis resulting from disruption of the central nervous system. It is a potent, noncompetitive antagonist of the gamma-aminobutyric acid (GABA) receptor. In humans, cicutoxin rapidly produces symptoms of nausea, emesis and abdominal pain, typically within 60 minutes of ingestion. This can lead to tremors, seizures, and death. LD50(mouse; i.p.) ~9 mg/kg History Johann Jakob Wepfer's book ''Cicutae Aquaticae Historia Et Noxae Commentario Illustrata'' was published in 1679; it contains the earliest published report of toxicity asso ... [...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) and in several Gymnopilus, Phellinus and Inonotus fungi. Some kavalactones are bioactive. They are responsible for the psychoactive, analgesic, euphoric and sedative effects of kava. Bioactivity Kava extract interacts with many pharmaceuticals and herbal medications. In human volunteers, in vivo inhibition includes CYP1A2 and CYP2E1 through use of probe drugs to measure inhibition. Research Its anxiolytic and hepatotoxic properties have been investigated. The major kavalactones (except for desmethoxyyangonin) potentiate GABAA receptors, which may underlie the anxiolytic and sedative properties of kava. Further, inhibition of the reuptake of norepinephrine and dopamine, binding to the CB1 receptor, inhibition of voltage-gated sodium and calcium channels, and monoamine oxidase B reversible inhibition are additional pharmacological actions that have been reported for k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inhalational Anaesthetic
An inhalational anesthetic is a chemical compound possessing general anesthetic properties that is 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 widely use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcohol (drug)
Alcohol, sometimes referred to by the chemical name ethanol, is the active ingredient in alcoholic drinks such as beer, wine, and distilled spirits (hard liquor). Alcohol is a central nervous system (CNS) depressant, decreasing Action potential, electrical activity of neurons in the brain, which causes the characteristic effects of alcohol intoxication ("drunkenness"). Among other effects, alcohol produces euphoria, anxiolytic, decreased anxiety, increased sociability, sedation, and impairment of cognitive, memory, motor control, motor, and sense, sensory function. Alcohol has a variety of adverse effects. Short-term effects of alcohol consumption, Short-term adverse effects include generalized impairment of neurocognitive function, dizziness, nausea, vomiting, and symptoms of hangover. Alcohol is addiction, addictive and can result in alcohol use disorder, Substance dependence, dependence, and Alcohol withdrawal syndrome, withdrawal upon cessation. The long-term effects of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbiturate
Barbiturates are a class of depressant, depressant drugs that are chemically derived from barbituric acid. They are effective when used medication, 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 recreational drug use, used recreationally for their anti-anxiety and sedative effects, and are thus prohibition of drugs, 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 t ... [...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 the ... [...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, depressant, sedative, hypnotic, anxiolytic drugs that are benzodiazepine-like in uses, such as for treating insomnia and anxiety. Nonbenzodiazepine pharmacodynamics are similar in mechanism of action to benzodiazepine drugs, acting as GABAA receptor positive allosteric modulator, GABAA receptor positive allosteric modulators of the benzodiazepine receptor, benzodiazepine site, and therefore exhibit similar benefits, side effects, and risks. However, nonbenzodiazepines have dissimilar or entirely different chemical structures, so are unrelated to benzodiazepines on a molecular level. Background Nonbenzodiazepines have demonstrated efficacy in treating sleep disorders. There is some limited evidence that suggests that drug tolerance, tolerance to nonbenzodiazepines is slower to develop than with benzodiazepines. However, data is limit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzodiazepine
Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, 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 Roche, Hoffmann–La Roche, which followed with the development of diazepam (Valium) three years later, 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, gamma-aminobutyric acid (GABA) at the GABAA receptor, GABAA receptor, resulting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allosteric
In the fields of biochemistry and pharmacology an allosteric regulator (or allosteric modulator) is a substance that binds to a site on an enzyme or receptor distinct from the active site, resulting in a conformational change that alters the protein's activity, either enhancing or inhibiting its function. In contrast, substances that bind directly to an enzyme's active site or the binding site of the endogenous ligand of a receptor are called orthosteric regulators or modulators. The site to which the effector binds is termed the ''allosteric site'' or ''regulatory site''. Allosteric sites allow effectors to bind to the protein, often resulting in a conformational change and/or a change in protein dynamics. Effectors that enhance the protein's activity are referred to as ''allosteric activators'', whereas those that decrease the protein's activity are called ''allosteric inhibitors''. Allosteric regulations are a natural example of control loops, such as feedback from downs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicuculline
Bicuculline is a phthalide-isoquinoline compound that is a light-sensitive competitive antagonist of GABAA receptors. It was originally identified in 1932 in plant alkaloid extracts and has been isolated from ''Dicentra cucullaria'', '' Adlumia fungosa'', and several ''Corydalis'' species (all in subfamily Fumarioideae, previously known as family Fumariaceae). Since it blocks the inhibitory action of GABA receptors, the action of bicuculline mimics epilepsy; it also causes convulsions. This property is utilized in laboratories around the world in the ''in vitro'' study of epilepsy, generally in hippocampal or cortical neurons in prepared brain slices from rodents. This compound is also routinely used to isolate glutamatergic (excitatory amino acid) receptor function. The action of bicuculline is primarily on the ionotropic GABAA receptors, which are ligand-gated ion channels concerned chiefly with the passing of chloride ions across the cell membrane, thus promoting an inhibi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
