Morphological and behavioural changes occur following the X-ray irradiation of the adult mouse olfactory neuroepithelium

• Published in: BMC neuroscience Vol. 13; no. 1; p. 134
• Main Authors: Cunha, Carla, Hort, Yvonne, Shine, John, Doyle, Kharen L
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 31-10-2012; BioMed Central; BMC
• Subjects: Adult stem cells; Analysis; Animals; Apoptosis; Apoptosis - radiation effects; Basic Helix-Loop-Helix Transcription Factors - biosynthesis; Cell Movement - radiation effects; Cell Proliferation - radiation effects; Design; Epithelial cells; Eye Proteins - biosynthesis; Health aspects; Homeodomain Proteins - biosynthesis; Irradiation; Male; Mice; Mice, Inbred C57BL; Morphology (Animals); Neuroepithelial Cells - cytology; Neuroepithelial Cells - radiation effects; Neurogenesis - radiation effects; Olfactory Bulb - cytology; Olfactory Bulb - radiation effects; Olfactory Marker Protein - biosynthesis; Olfactory nerve; Olfactory neuroepithelium; Olfactory Receptor Neurons - cytology; Olfactory Receptor Neurons - radiation effects; Paired Box Transcription Factors - biosynthesis; PAX6 Transcription Factor; Physiological aspects; Proliferation; Repressor Proteins - biosynthesis; Smell - radiation effects; Statistical analysis; Stem cells; Stem Cells - radiation effects; Studies; Time Factors; X-ray irradiation; X-rays; Australia
• ISSN: 1471-2202; 1471-2202
• DOI: 10.1186/1471-2202-13-134

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.
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.
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.