Solitary chemoreceptor cell proliferation in adult nasal epithelium.
Nasal trigeminal chemosensitivity in mice and rats is mediated in part by solitary chemoreceptor cells (SCCs) in the nasal epithelium (Finger et al., 2003). Many nasal SCCs express the G-protein alpha-gustducin as well as other elements of the bitter-taste signaling cascade including phospholipase Cbeta2, TRPM5 and T2R bitter-taste receptors. While some populations of sensory cells are replaced throughout life (taste and olfaction), others are not (hair cells and carotid body chemoreceptors). These experiments were designed to test whether new SCCs are generated within the epithelium of adult mice. Wild type C57/B6 mice were injected with the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) to label dividing cells. At various times after injection (1-40 days), the mice were perfused with 4% paraformaldehyde and prepared for dual-label immunocytochemistry. Double labeled cells were detected as early as 3 days post BrdU injection and remained for as long as 12 days post-injection suggesting that SCCs do undergo turnover like the surrounding nasal epithelium. No BrdU labeled cells were detected after 24 days suggesting relatively rapid replacement of the SCCs.
Gulbransen
Brian D
BD
Department of Cellular and Developmental Biology, Rocky Mountain Taste and Smell Center, Neuroscience Program, University of Colorado at Denver Health Sciences Center, Mail Stop 8108, P.O. Box 6511, Aurora, CO 80045, USA. brian.gulbransen@uchsc.edu
Finger
Thomas E
TE
D000818:Animals; D001973:Bromodeoxyuridine; D002452:Cell Count; D049109:Cell Proliferation; D002628:Chemoreceptor Cells / Q000737:chemistry* / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D019204:GTP-Binding Proteins / Q000032:analysis; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D009297:Nasal Mucosa / Q000737:chemistry* / Q000166:cytology* / Q000502:physiology; D054799:Phospholipase C beta; D043562:Receptors, G-Protein-Coupled / Q000032:analysis; D015398:Signal Transduction / Q000502:physiology; D050053:TRPM Cation Channels / Q000032:analysis; D013997:Time Factors; D015293:Transducin / Q000032:analysis; D010738:Type C Phospholipases / Q000032:analysis; D000098706:Taste Receptors, Type 2
D007527:Isoenzymes; D043562:Receptors, G-Protein-Coupled; D050053:TRPM Cation Channels; C498617:Trpm5 protein, mouse; D000098706:Taste Receptors, Type 2; C075192:gustducin; D010738:Type C Phospholipases; D054799:Phospholipase C beta; D019204:GTP-Binding Proteins; D015293:Transducin; D001973:Bromodeoxyuridine