Sandbox 77: Difference between revisions

5-HT, Serotonin, receptors are found on the membrane of neurons in the central nervous system and peripheral nervous system. These receptors allow for the body to respond to serotonin and regulate many biological pathways. Serotonin, also known as 5 hydroxytryptamine, is an endogenous neurotransmitter made from tryptophan and is largely found in the gastrointestinal tract. It is known to regulate mood, appetite, digestion, circadian rhythm, learning and internal temperature regulation. It is can be an inhibitory or excitatory neurotransmitter that is released into the synaptic space and can bind to receptors on the postsynaptic neuron or be taken back up into the presynaptic neuron via Serotonin reuptake transporters.<ref>Goodsell D. ''Serotonin Receptor''. RCSB PDB-101 (2013) [http://www.rcsb.org/pdb/101/motm.do?momID=164 DOI: 10.2210/rcsb_pdb/mom_2013_8]</ref> 5-HT receptors are classified into 7 different subfamilies (5-HT1, 5-HT2, 5-HT3, etc.) by signaling mechanisms and homology of structure. All 5-HT receptors are known to have G-protein linked pathways except for the 5-HT3 receptor which acts as an ion channel. <ref name ="one">Wang C, Jiang Y, Ma J, Wu H, Wacker D, Katritch V, Han GW, Liu W, Huang XP, Vardy E, McCorvy JD, Gao X, Zhou EZ, Melcher K, Zhang C, Bai F, Yang H, Yang L, Jiang H, Roth BL, Cherezov V, Stevens RC, Xu HE. Structural Basis for Molecular Recognition at Serotonin Receptors. Science. 2013 May 3; 340(6132): 610–614. PMID:3644373 [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3644373/]</ref>

5-HT3 antagonists have a wide variety of uses such as treating nausea, vomiting, irritable bowel syndrome and mood disorders. Once a 5-HT3 antagonist has bound to a 5-HT3 receptor, serotonin binding is inhibited.<ref>Brunton, Laurence L.; Lazo, John S.; Parker, Keith L. (2006). Goddman & Gilman's The Pharmacological Basis of Therapeutics. New York: McGraw-Hill. pp. 1000–3. ISBN 978-0-07-142280-2.</ref> 4i (N-(3-chloro-2-methylphenyl)quinoxalin-2-carboxamide) is a 5-HT3 antagonist shown to act as an antidepressant in diabetes-induced depression in mice; it resulted in a significant decrease in 5-HT in the midbrain after administration. <ref>Gupta D, Devadoss T, Mahesh R. ''A novel 5HT 3 antagonist 4i (N-(3-chloro-2-methylphenyl) quinoxalin-2-carboxamide) prevents diabetes-induced depressive phenotypes in mice: Modulation of serotonergic system.'' Behavioural brain research 297 (2016): 41-50. [http://www.sciencedirect.com/science/article/pii/S0166432815302217 DOI:10.1016/j.bbr.2015.10.007]</ref>