TRPV2, a capsaicin receptor homologue, is expressed predominantly in the neurotrophin-3-dependent subpopulation of primary sensory neurons.
TRPV2, a member of transient receptor potential ion channels, responds to high-threshold noxious heat, but neither to capsaicin nor to proton. Although TRPV2 is expressed in medium- to large-sized dorsal root ganglion (DRG) neurons with myelinated fibers in adult rodents, little is known about the neurotrophin dependence of TRPV2-positive neurons in the developing and adult DRGs of mice. In the present study, using immunohistochemistry, we found that TRPV2 was first expressed in DRG neurons at embryonic day (E) 11.5, when neither TRPV1 nor TRPM8 was detected yet. Double-immunofluorescence staining revealed that tyrosine kinase receptor C (TrkC) was expressed in most of TRPV2-positive DRG neurons at E11.5 and E13.5. In addition, the percentage of TRPV2-positive neurons in the total DRG neurons at E13.5 reached the same as that of adulthood. In adult DRGs, TrkC and Ret were expressed in 68% and 25% of TRPV2-positive neurons, respectively. These results suggest that TRPV2 is expressed predominantly in the NT-3-dependent subpopulation of DRG neurons throughout development and in adult mice.
Tamura
S
S
Department of Anatomy and Neurobiology, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509 Japan.
Morikawa
Y
Y
Senba
E
E
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D015220:Calcium Channels / Q000378:metabolism*; D002452:Cell Count / Q000379:methods; D004268:DNA-Binding Proteins / Q000378:metabolism; D004622:Embryo, Mammalian; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology* / Q000196:embryology / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D007150:Immunohistochemistry / Q000379:methods; D007473:Ion Channels / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009046:Motor Neurons / Q000145:classification / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism; D020933:Neurotrophin 3 / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D011247:Pregnancy; D020813:Receptor, trkB / Q000378:metabolism; D020812:Receptor, trkC / Q000378:metabolism; D012867:Skin / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D013116:Spinal Cord / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D050053:TRPM Cation Channels; D050916:TRPV Cation Channels; D044767:Ubiquitin-Protein Ligases; D000070584:Tripartite Motif Proteins
D015220:Calcium Channels; D004268:DNA-Binding Proteins; D007473:Ion Channels; D009363:Neoplasm Proteins; D020933:Neurotrophin 3; D009687:Nuclear Proteins; D020813:Receptor, trkB; D020812:Receptor, trkC; D050053:TRPM Cation Channels; D050916:TRPV Cation Channels; D044767:Ubiquitin-Protein Ligases; C492297:TRPM8 protein, mouse; C485717:Trpv2 protein, mouse; C489296:Trim27 protein, mouse; D000070584:Tripartite Motif Proteins