RT Journal Article SR Electronic T1 Developmental expression of trkC, the neurotrophin-3 receptor, in the mammalian nervous system JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 14 OP 28 DO 10.1523/JNEUROSCI.14-01-00014.1994 VO 14 IS 1 A1 Lamballe, F A1 Smeyne, RJ A1 Barbacid, M YR 1994 UL http://www.jneurosci.org/content/14/1/14.abstract AB The mammalian trkC gene encodes a tyrosine protein kinase that serves as a functional receptor for neurotrophin-3 (NT-3). Here, we report that trkC is widely expressed in the developing and adult nervous system. Using in situ hybridization, we first detect trkC transcripts in the telencephalon and spinal cord of embryonic day 9.5 mouse embryos. In later embryonic development, trkC is expressed in various structures of the CNS including the caudatoputamen, septal nuclei, cerebellum, and brainstem. In the PNS, trkC hybridization appears to correlate, both temporally and spatially, with the outgrowth of axons toward their peripheral targets. trkC transcripts were also identified in the autonomous enteric nervous system as well as in some non-neural tissues such as the wall of the aorta and the acini of the submaxillary and sublingual glands. In the adult mouse, trkC gene expression is heterogeneously distributed throughout the brain, with highest levels in limbic and diencephalic structures. These results indicate that the trkC gene is widely expressed in the three identified branches of the mammalian nervous system and appears to correlate with the expression of NT-3, its cognate ligand. The apparent colocalization of trkC transcripts with NT-3 raises the possibility this neurotrophin exerts its trophic effects by a paracrine and/or autocrine mechanism.