title: Distribution of M-channel subunits KCNQ2 and KCNQ3 in rat hippocampus.
abstract: Neuronal M-channels are low threshold, slowly activating and non-inactivating, voltage dependent K(+) channels that play a crucial role in controlling neuronal excitability. The native M-channel is composed of heteromeric or homomeric assemblies of subunits belonging to the Kv7/KCNQ family, with KCNQ2/3 heteromers being the most abundant form. KCNQ2 and KCNQ3 subunits have been found to be expressed in various neurons in the central and peripheral nervous system of rodents and humans. Previous evidence shows preferential localization of both subunits to axon initial segments, somata and nodes of Ranvier. In this work, we show the distribution and co-localization of KCNQ2 and KCNQ3 subunits throughout the hippocampal formation, via immunostaining experiments on unfixed rat brain slices and confocal microscopy. We find intense localization and colocalization to the axonal initial segment in several regions of the hippocampus, as well as staining for non-neuronal cells in the area of the lateral ventricle. We did not observe colocalization of KCNQ2 or KCNQ3 with the presynaptic protein, synaptophysin.
authors.affiliation: Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
authors.forename: Felicia
authors.initials: F
authors.lastname: Klinger
authors.forename: Georgianna
authors.initials: G
authors.lastname: Gould
authors.forename: Stefan
authors.initials: S
authors.lastname: Boehm
authors.forename: Mark S
authors.initials: MS
authors.lastname: Shapiro
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D006624:Hippocampus / Q000737:chemistry* / Q000378:metabolism; D007150:Immunohistochemistry; D051658:KCNQ2 Potassium Channel / Q000032:analysis* / Q000096:biosynthesis; D051659:KCNQ3 Potassium Channel / Q000032:analysis* / Q000096:biosynthesis; D018613:Microscopy, Confocal; D021122:Protein Subunits / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D051658:KCNQ2 Potassium Channel; D051659:KCNQ3 Potassium Channel; C496915:Kcnq2 protein, rat; C496918:Kcnq3 protein, rat; D021122:Protein Subunits