title: Localization of endogenous morphine-like compounds in the mouse spinal cord.
abstract: Morphine, codeine, morphine-6-glucuronide, and morphine-3-glucuronide are synthesized de novo in mammalian cells and in the central nervous system. Knowledge on endogenous morphine-like compound distribution in the adult mouse brain has been recently improved, and new hypotheses have been suggested about the potential implications in brain physiology. Endogenous morphine-like compounds have been shown to be synthesized in the spinal cord, but their localization is unknown. Here we describe the distribution of endogenous morphine-like compounds (morphine and/or its glucuronides and/or codeine) in the adult mouse spinal cord using a well-validated antibody. By using different microscopy approaches, we found the presence of morphine, codeine, or morphine glucuronides in γ-aminobutyric acid (GABA)-ergic neurons and astrocytes of the spinal cord. Whereas GABAergic neurons containing endogenous morphine-like compounds were located primarily in the ventral horn, astrocytes that were labeled for morphine-like compounds were found throughout the gray matter and the white matter. Our study demonstrates the possibility that endogenous morphine-like compounds in the central nervous system have other functions beyond their analgesic functions.
authors.affiliation: Nociception and Pain Department, Centre National de la Recherche Scientifique and University of Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67084 Strasbourg, France.
authors.forename: Alexis
authors.initials: A
authors.lastname: Laux
authors.forename: François
authors.initials: F
authors.lastname: Delalande
authors.forename: Jinane
authors.initials: J
authors.lastname: Mouheiche
authors.forename: Denise
authors.initials: D
authors.lastname: Stuber
authors.forename: Alain
authors.initials: A
authors.lastname: Van Dorsselaer
authors.forename: Enrica
authors.initials: E
authors.lastname: Bianchi
authors.forename: Erwan
authors.initials: E
authors.lastname: Bezard
authors.forename: Pierrick
authors.initials: P
authors.lastname: Poisbeau
authors.forename: Yannick
authors.initials: Y
authors.lastname: Goumon
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D003061:Codeine / Q000032:analysis / Q000096:biosynthesis; D059330:GABAergic Neurons / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D009020:Morphine / Q000032:analysis / Q000096:biosynthesis; D009022:Morphine Derivatives / Q000032:analysis* / Q000378:metabolism; D013116:Spinal Cord / Q000378:metabolism*
chemical_list: D009022:Morphine Derivatives; C035349:morphine-6-glucuronide; D009020:Morphine; C018108:morphine-3-glucuronide; D003061:Codeine