Solitary chemoreceptor cell survival is independent of intact trigeminal innervation.
Nasal solitary chemoreceptor cells (SCCs) are a population of specialized chemosensory epithelial cells presumed to broaden trigeminal chemoreceptivity in mammals (Finger et al. [2003] Proc Natl Acad Sci USA 100:8981-8986). SCCs are innervated by peptidergic trigeminal nerve fibers (Finger et al. [2003]) but it is currently unknown if intact innervation is necessary for SCC development or survival. We tested the dependence of SCCs on innervation by eliminating trigeminal nerve fibers during development with neurogenin-1 knockout mice, during early postnatal development with capsaicin desensitization, and during adulthood with trigeminal lesioning. Our results demonstrate that elimination of innervation at any of these times does not result in decreased SCC numbers. In conclusion, neither SCC development nor mature cell maintenance is dependent on intact trigeminal innervation.
Gulbransen
Brian
B
Department of Cell and Developmental Biology, Neuroscience Program and Rocky Mountain Taste and Smell Center, School of Medicine University of Colorado Denver, Aurora, Colorado 80045, USA.
Silver
Wayne
W
Finger
Thomas E
TE
D000818:Animals; D000831:Animals, Newborn; D017763:Autonomic Denervation / Q000379:methods; D051792:Basic Helix-Loop-Helix Proteins / Q000172:deficiency; D002211:Capsaicin / Q000494:pharmacology; D002470:Cell Survival; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000502:physiology*; D004622:Embryo, Mammalian; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009297:Nasal Mucosa / Q000166:cytology* / Q000294:innervation; D009419:Nerve Tissue Proteins / Q000172:deficiency; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018689:Sensory System Agents / Q000494:pharmacology; D050053:TRPM Cation Channels / Q000378:metabolism; D014276:Trigeminal Nerve / Q000166:cytology* / Q000502:physiology
D051792:Basic Helix-Loop-Helix Proteins; D002211:Capsaicin; D049452:Green Fluorescent Proteins; D009419:Nerve Tissue Proteins; D018689:Sensory System Agents; D050053:TRPM Cation Channels; C498617:Trpm5 protein, mouse; C486336:Neurog1 protein, mouse