title: Specific localization of five phosphatidylcholine species in the cochlea by mass microscopy.
abstract: Phosphatidylcholine (PC), a phospholipid, is a basic structural component of cell membranes. PC species exhibit various binding patterns with fatty acids; however, the distributions of PC species have not been studied in the cochlea. In recent years, imaging mass spectrometry has been used as a biomolecular visualization technique in medical and biological sciences. We recently developed a 'mass microscope' consisting of a mass spectrometry imager with high spatial resolution equipped with an atmospheric-pressure matrix-assisted laser desorption/ionization and quadrupole ion trap time-of-flight analyzer. In this study, we applied the mass microscope to analyze cochlear tissue sections. The imager allowed visualization of the localization of PC species in each region of the cochlea. The structures of the PC species were determined using tandem mass spectrometry. PC(16:0/18:1) was highly localized in the organ of Corti and the stria vascularis. PC(16:0/18:2) was mainly observed in the spiral ligament. PC(16:0/16:1) was found primarily in the organ of Corti. These distributional differences may be associated with the cellular architecture of these cochlear regions.
authors.affiliation: Department of Otolaryngology, Molecular Imaging Frontier Research Center, Hamamatsu University School of Medicine, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Takizawa
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Mizuta
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hayasaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakanishi
authors.forename: Jun
authors.initials: J
authors.lastname: Okamura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mineta
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Setou
mesh_terms: D000818:Animals; D003051:Cochlea / Q000737:chemistry*; D006168:Guinea Pigs; D010713:Phosphatidylcholines / Q000032:analysis*; D053719:Tandem Mass Spectrometry
chemical_list: D010713:Phosphatidylcholines