title: Morphological and behavioural changes occur following the X-ray irradiation of the adult mouse olfactory neuroepithelium.
abstract: BACKGROUND
  The olfactory neuroepithelium lines the upper nasal cavity and is in direct contact with the external environment and the olfactory bulbs. The ability to self-renew throughout life and the reproducible recovery after injury, make it a model tissue to study mechanisms underlying neurogenesis. In this study, X-rays were used to disrupt proliferating olfactory stem cell populations and to assess their role in the cellular and morphological changes involved in olfactory neurogenic processes.
  
  
  RESULTS
  We have analysed the histological and functional effects of a sub-lethal dose of X-rays on the adult mouse olfactory neuroepithelium at 2 hours, 24 hours, 1 week, 2 weeks and 5 weeks. We have shown an immediate cessation of proliferating olfactory stem cells as shown by BrdU, Ki67 and pH3 expression. At 24 hours there was an increase in the neural transcription factors Mash1 and Pax6 expression, and a disruption of the basal lamina and increase in glandular cell marker expression at 1 week post-irradiation. Coincident with these changes was an impairment of the olfactory function in vivo.
  
  
  CONCLUSIONS
  We have shown significant changes in basal cell proliferation as well as morphological changes in the olfactory neuroepithelium following X-ray irradiation. There is involvement of the basal lamina as well as a clear role for glandular and sustentacular cells.
authors.affiliation: Neuroscience Research Program, Garvan Institute of Medical Research, Sydney, Australia.
authors.forename: Carla
authors.initials: C
authors.lastname: Cunha
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Hort
authors.forename: John
authors.initials: J
authors.lastname: Shine
authors.forename: Kharen L
authors.initials: KL
authors.lastname: Doyle
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D051792:Basic Helix-Loop-Helix Proteins / Q000096:biosynthesis; D002465:Cell Movement / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D005136:Eye Proteins / Q000096:biosynthesis; D018398:Homeodomain Proteins / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D046569:Neuroepithelial Cells / Q000166:cytology* / Q000528:radiation effects*; D055495:Neurogenesis / Q000528:radiation effects*; D009830:Olfactory Bulb / Q000166:cytology / Q000528:radiation effects*; D051842:Olfactory Marker Protein / Q000096:biosynthesis; D018034:Olfactory Receptor Neurons / Q000166:cytology / Q000528:radiation effects*; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000096:biosynthesis; D012097:Repressor Proteins / Q000096:biosynthesis; D012903:Smell / Q000528:radiation effects*; D013234:Stem Cells / Q000528:radiation effects; D013997:Time Factors
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D051842:Olfactory Marker Protein; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; C499317:Ascl1 protein, mouse; C497598:Omp protein, mouse; C000605732:Pax6 protein, mouse