title: Co-localization of TRPV2 and insulin-like growth factor-I receptor in olfactory neurons in adult and fetal mouse.
abstract: TRPV2, a member of the transient receptor potential family, has been isolated as a capsaicin-receptor homolog and is thought to respond to noxious heat. Here we show that TRPV2 mRNA is predominantly expressed in the subpopulation of olfactory sensory neurons (OSNs). We carried out histochemical analyses of TRPV2 and insulin-like growth factor-I receptor (IGF-IR) using in situ hybridization and immunofluorescence in the adult olfactory system. In olfactory mucosa, intensive TRPV2 immunostaining was observed at the olfactory axon bundles but not at the soma. TRPV2-positive labeling was preferentially found in the olfactory nerve layer in the olfactory bulb (OB). Furthermore, we demonstrated that a positive signal for IGF-IR mRNA was detected in OSNs expressing TRPV2 mRNA. In embryonic stages, TRPV2 immunoreactivity was observed on axon bundles of developing OSNs in the nasal region starting from 12.5 d of gestation and through fetal development. Observations in this study suggest that TRPV2 coupled with IGF-IR localizes to growing olfactory axons in the OSNs.
authors.affiliation: Department of Sensory Physiology, Asahikawa Medical University.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Matsui
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Noguchi
authors.forename: Kaoru
authors.initials: K
authors.lastname: Takakusaki
authors.forename: Makoto
authors.initials: M
authors.lastname: Kashiwayanagi
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D005333:Fetus / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000378:metabolism*; D009830:Olfactory Bulb / Q000166:cytology*; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000235:genetics / Q000378:metabolism*; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; D012333:RNA, Messenger; D050916:TRPV Cation Channels; C485717:Trpv2 protein, mouse; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1