Muscarinic acetylcholine receptors (different subtypes M1–M5)
There are two main types of cholinergic receptors – muscarinic and nicotinic acetylcholine receptors. The muscarinic receptors are further classified into M1–M5 receptors. The receptors are distinguished by location, post-receptor signalling pathway and agonist or antagonist interaction. The M1 receptor is the most significant receptor in the central nervous system and is highly expressed in the brain and nerves. Recently, muscarinic M1 receptor agonists have become the focus of research into the treatment of Alzheimer’s disease. M1 agonists may increase acetylcholine transmission in the brain and alleviate some of the symptoms of Alzheimer’s disease.
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References
Cholinoceptor-activating and cholinesterase inhibiting drugs. In: Basic and clinical pharmacology, 8th edition. Katzung BG. USA: The McGraw Hill Companies, Inc, 2001:92–106.
Cholinergic transmission. In: Pharmacology, 4th edition. Rang HP, Dale MM and Ritter JM. Edinburgh, UK: Harcourt Publishers Ltd, 2001:110–138.
Neuroscience Research at The University of Toledo. http://www.neurosci.pharm.utoledo.edu/MBC3320/muscarinic.htm. Accessed on 9 January 2003.