title: Mu-opioid receptor (MOR) expression in the human spiral ganglia.
abstract: Opioid peptides and their receptors have been localized to the inner ear of the rat and guinea pig mammalian models. The expression of mu opioid receptor (MOR) in the human and mouse cochlea is not yet known. We present MOR protein localization by immunohistochemistry and mRNA expression by in situ hybridization in the human and mouse spiral ganglia (SG) and organ of Corti. In the human most of the (SG) neurons were immunoreactive; a subset was non-immunoreactive. In situ hybridization revealed a similar labeling pattern across the neurons of the SG. A similar distribution MOR pattern was demonstrated in the mouse SG. In the mouse organ of Corti MOR was expressed in inner and outer hair cells. Fibers underneath the inner hair cells were also MOR immunoreactive. These results are consistent with a role of MOR in neuromodulation of the auditory periphery. The present results show that the expression of MORs is well-conserved across multiple mammalian species, indicative of an important role in auditory processing.
authors.affiliation: Department of Head and Neck Surgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90024, USA.
authors.forename: Kimanh D
authors.initials: KD
authors.lastname: Nguyen
authors.affiliation: Neurology Department, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90024, USA.
authors.forename: Donald
authors.initials: D
authors.lastname: Mowlds
authors.affiliation: Department of Head and Neck Surgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90024, USA.
authors.forename: Ivan A
authors.initials: IA
authors.lastname: Lopez
authors.affiliation: Department of Head and Neck Surgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90024, USA.
authors.forename: Seiji
authors.initials: S
authors.lastname: Hosokawa
authors.affiliation: Department of Head and Neck Surgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90024, USA.
authors.forename: Akira
authors.initials: A
authors.lastname: Ishiyama
authors.affiliation: Neurology Department, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90024, USA. Electronic address: gishiyama@mednet.ucla.edu.
authors.forename: Gail
authors.initials: G
authors.lastname: Ishiyama
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001344:Autopsy; D003051:Cochlea / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D017450:Receptors, Opioid, mu / Q000096:biosynthesis / Q000378:metabolism*; D013136:Spiral Ganglion / Q000378:metabolism*; D013701:Temporal Bone / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D017450:Receptors, Opioid, mu
keywords: Afferent terminals; Cochlea; Neuropeptides; Opioid receptors; Spiral ganglia neurons