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Muscarinic Acetylcholine Receptor M4
The muscarinic acetylcholine receptor M4, also known as the cholinergic receptor, muscarinic 4 (CHRM4), is a protein that, in humans, is encoded by the ''CHRM4'' gene. Function M4 muscarinic receptors are coupled to Gi/o heterotrimeric proteins. They function as inhibitory autoreceptors for acetylcholine. Activation of M4 receptors inhibits acetylcholine release in the striatum. The M2 subtype of acetylcholine receptor functions similarly as an inhibitory autoreceptor to acetylcholine release, albeit functioning actively primarily in the hippocampus and cerebral cortex. Muscarinic acetylcholine receptors possess a regulatory effect on dopaminergic neurotransmission. Activation of M4 receptors in the striatum inhibit D1-induced locomotor stimulation in mice. M4 receptor-deficient mice exhibit increased locomotor simulation in response to D1 agonists, amphetamine and cocaine. Neurotransmission in the striatum influences extrapyramidal motor control, thus alterations in M4 ac ... [...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] |
Extrapyramidal System
In anatomy, the extrapyramidal system is a part of the motor system network causing involuntary actions. The system is called ''extrapyramidal'' to distinguish it from the tracts of the motor cortex that reach their targets by traveling through the pyramids of the medulla. The pyramidal tracts (corticospinal tract and corticobulbar tracts) may directly innervate motor neurons of the spinal cord or brainstem ( anterior (ventral) horn cells or certain cranial nerve nuclei), whereas the extrapyramidal system centers on the modulation and regulation (indirect control) of anterior (ventral) horn cells. Extrapyramidal tracts are chiefly found in the reticular formation of the pons and medulla, and target lower motor neurons in the spinal cord that are involved in reflexes, locomotion, complex movements, and postural control. These tracts are in turn modulated by various parts of the central nervous system, including the nigrostriatal pathway, the basal ganglia, the cerebellum, the vesti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscarinic Acetylcholine Receptor
Muscarinic acetylcholine receptors, or mAChRs, are acetylcholine receptors that form G protein-coupled receptor complexes in the cell membranes of certain neurons and other cells. They play several roles, including acting as the main end-receptor stimulated by acetylcholine released from postganglionic fibers in the parasympathetic nervous system. Muscarinic receptors are so named because they are more sensitive to muscarine than to nicotine. Their counterparts are nicotinic acetylcholine receptors (nAChRs), receptor ion channels that are also important in the autonomic nervous system. Many drugs and other substances (for example pilocarpine and scopolamine) manipulate these two distinct receptors by acting as selective agonists or antagonists. Function Acetylcholine (ACh) is a neurotransmitter found in the brain, neuromuscular junctions and the autonomic ganglia. Muscarinic receptors are used in the following roles: Recovery receptors ACh is always used as the neur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphenhydramine
Diphenhydramine (DPH) is an antihistamine and sedative mainly used to treat allergies, insomnia, and symptoms of the common cold. It is also less commonly used for tremor in parkinsonism, and nausea. It is taken by mouth, injected into a vein, injected into a muscle, or applied to the skin. Maximal effect is typically around two hours after a dose, and effects can last for up to seven hours. Common side effects include sleepiness, poor coordination and an upset stomach. Its use is not recommended in young children or the elderly. There is no clear risk of harm when used during pregnancy; however, use during breastfeeding is not recommended. It is a first generation H1-antihistamine and ethanolamine and works by blocking certain effects of histamine, which produces its antihistamine and sedative effects. Diphenhydramine is also a potent anticholinergic, which means it also works as a deliriant at higher than recommended doses as a result. Its sedative and deliriant effects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropicamide
Tropicamide, sold under the brand name Mydriacyl among others, is a medication used to dilate the pupil and help with examination of the eye. Specifically it is used to help examine the back of the eye. It is applied as eye drops. Effects occur within 40 minutes and last for up to a day. Common side effects include blurry vision, increased intraocular pressure, and sensitivity to light. Another rare but severe side effect is psychosis, particularly in children. It is unclear if use during pregnancy is safe for the fetus. Tropicamide is in the antimuscarinic part of the anticholinergic family of medications. It works by making the muscles within the eye unable to respond to nerve signals. Tropicamide was approved for medical use in the United States in 1960. It is on the World Health Organization's List of Essential Medicines. Medical use Tropicamide is an antimuscarinic drug that produces short acting mydriasis (dilation of the pupil) and cycloplegia when applied as eye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PD-0298029
PD-0298029 is a drug which acts as a selective antagonist for the muscarinic acetylcholine receptor M4. It was developed for the treatment of Parkinson's disease, but poor bioavailability and rapid metabolism in animal studies have meant its use is largely limited to ''in vitro'' research into the M4 and other muscarinic receptors.Progress in Medicinal Chemistry 43. (2005). Chapter 4, Muscarinic Receptor Subtype Pharmacology and Physiology, by Richard M Eglen. pp 128-129. See also * PD-102,807 PD-102,807 is a drug which acts as a selective antagonist for the muscarinic acetylcholine receptor M4. It is used in scientific research for studying the effects of the different muscarinic receptor subtypes in the body and brain. See also * P ... References Parkinson's disease Muscarinic antagonists {{nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PD-102,807
PD-102,807 is a drug which acts as a selective antagonist for the muscarinic acetylcholine receptor M4. It is used in scientific research for studying the effects of the different muscarinic receptor subtypes in the body and brain. See also * PD-0298029 PD-0298029 is a drug which acts as a selective antagonist for the muscarinic acetylcholine receptor M4. It was developed for the treatment of Parkinson's disease, but poor bioavailability and rapid metabolism in animal studies have meant its use ... References {{Muscarinic acetylcholine receptor modulators Muscarinic antagonists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Himbacine
Himbacine is an alkaloid isolated from the bark of Australian magnolias. Himbacine has been synthesized using a Diels-Alder reaction as a key step. Himbacine's activity as a muscarinic receptor antagonist, with specificity for the muscarinic acetylcholine receptor M2, made it a promising starting point in Alzheimer's disease Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ... research. The development of a muscarinic antagonist based on himbacine failed but an analog, vorapaxar, has been approved by the FDA as a thrombin receptor antagonist. References Muscarinic antagonists Naphthofurans Piperidine alkaloids Lactones {{pharmacology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicycloverine
Dicycloverine, also known as dicyclomine, sold under the brand name Bentyl in the US, is a medication that is used to treat spasms of the intestines such as occur in irritable bowel syndrome. It is taken by mouth or by injection into a muscle. While it has been used in baby colic and enterocolitis, evidence does not support these uses. Common side effects include dry mouth, blurry vision, weakness, sleepiness, and lightheadedness. Serious side effects may include psychosis and breathing problems in babies. Use in pregnancy appears to be safe while use during breastfeeding is not recommended. How it works is not entirely clear. Dicycloverine was approved for medical use in the United States in 1950. It is available as a generic medication. In 2020, it was the 147th most commonly prescribed medication in the United States, with more than 4million prescriptions. Medical uses Dicyclomine is used to treat the symptoms of irritable bowel syndrome Irritable bowel syndrome (IB ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AFDX-384
AFDX-384 (BIBN-161) is a drug which acts as a selective antagonist of the muscarinic acetylcholine receptors, with selectivity for the M2 and M4 subtypes. It is used mainly for mapping the distribution of M2 and M4 muscarinic receptors in the brain, and studying their involvement in the development and treatment of dementia and schizophrenia. See also * Pirenzepine Pirenzepine (Gastrozepin), an M1 selective antagonist, is used in the treatment of peptic ulcers, as it reduces gastric acid secretion and reduces muscle spasm. It is in a class of drugs known as muscarinic receptor antagonists - acetylchol ... (M1 selective antagonist) References {{Muscarinic acetylcholine receptor modulators Muscarinic antagonists Piperidines Ureas Benzodiazepines Pyridodiazepines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxotremorine
Oxotremorine is a drug that acts as a selective muscarinic acetylcholine receptor agonist. Oxotremorine produces ataxia, tremor and spasticity, similar to those symptoms seen in Parkinsonism, and has thus become a research tool in experimental studies aimed at determining more effective anti-Parkinsonian drugs. Oxotremorine also produces antipsychotic effects. References See also * Tremorine Tremorine is a drug which is used in scientific research to produce tremor in animals. This is used for the development of drugs for the treatment of Parkinson's disease, as tremor is a major symptom which is treated by anti-Parkinson's drugs. Bet ... Alkyne derivatives Pyrrolidones Experimental drugs {{nervous-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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