title: 5-HT2a receptors in rat sciatic nerves and Schwann cell cultures.
abstract: Pharmacological approaches and optical recordings have shown that Schwann cells of a myelinating phenotype are activated by 5-HT upon its interaction with the 5-HT(2A) receptor (5-HT(2A)R). In order to further characterize the expression and distribution of this receptor in Schwann cells, we examined rat sciatic nerve and cultured rat Schwann cells using probes specific to 5-HT(2A)R protein mRNA. We also examined the endogenous sources of 5-HT in rat sciatic nerve by employing both histochemical stains and an antibody that specifically recognizes 5-HT. Rat Schwann cells of a myelinating phenotype contained both 5-HT(2A)R protein and mRNA. In the healthy adult rat sciatic nerve, 5-HT(2A)Rs were evenly distributed along the outermost portion of the Schwann cell plasma membrane and within the cytoplasm. The most prominent source of 5-HT was within granules of the endoneurial mast cells, closely juxtaposed to Schwann cells within myelinating sciatic nerves. These results support the hypothesis that the 5-HT receptors expressed by rat Schwann cells in vivo are activated by the release of 5-HT from neighboring mast cells.
authors.affiliation: National Center for Microscopy and Imaging Research at San Diego, Department of Neurosciences, University of California, San Diego, La Jolla, California, USA. ggaietta@ncmir.ucsd.edu
authors.forename: Guido M
authors.initials: GM
authors.lastname: Gaietta
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Yoder
authors.forename: Tom
authors.initials: T
authors.lastname: Deerinck
authors.forename: Karen
authors.initials: K
authors.lastname: Kinder
authors.forename: Abraham
authors.initials: A
authors.lastname: Hanono
authors.forename: Areum
authors.initials: A
authors.lastname: Han
authors.forename: Chun
authors.initials: C
authors.lastname: Wu
authors.forename: Mark H
authors.initials: MH
authors.lastname: Ellisman
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002462:Cell Membrane / Q000276:immunology / Q000648:ultrastructure; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D003711:Demyelinating Diseases / Q000276:immunology / Q000503:physiopathology; D007150:Immunohistochemistry; D008264:Macrophages / Q000276:immunology; D008407:Mast Cells / Q000276:immunology; D008854:Microscopy, Electron; D009186:Myelin Sheath / Q000276:immunology* / Q000648:ultrastructure; D009413:Nerve Fibers, Myelinated / Q000276:immunology* / Q000648:ultrastructure; D010525:Peripheral Nerves / Q000276:immunology / Q000648:ultrastructure; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A / Q000235:genetics / Q000378:metabolism*; D012583:Schwann Cells / Q000276:immunology* / Q000648:ultrastructure; D012584:Sciatic Nerve / Q000254:growth & development* / Q000276:immunology* / Q000648:ultrastructure; D012701:Serotonin / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D044402:Receptor, Serotonin, 5-HT2A; D012701:Serotonin