Coexpression of trk family members and low-affinity neurotrophin receptors in rat dorsal root ganglion neurons.

We examined the colocalization of trk family and low-affinity neurotrophin receptor (LANR) mRNAs by means of in situ hybridization histochemistry in rat dorsal root ganglion (DRG) neurons. About 35-40%, 5%, and 15-20% of DRG neurons were positive for trkA, trkB, and trkC mRNAs, respectively. Each member of the trk family was coexpressed with LANR. The trkB mRNA-expressing neurons essentially lacked trkA and trkC mRNAs, and most of trkA and trkC mRNAs-expressing neurons (85-90%) belonged to different subpopulations, suggesting that they are involved in different functions.