LOCALIZATION OF NEUROTROPHIN RECEPTORS IN OLFACTORY EPITHELIUM AND BULB

WE used in situ hybridization to localize trk, trkB and trkC mRNA, in rat and cat olfactory bulb. Expression of mRNA encoding truncated trkB receptors was seen in all layers, while only very modest full-length trkB expression could be detected. trkC hybridization was seen in all layers, most dense in the mitral cell layer. The localization of full- length tyrosine kinase trkB receptor in olfactory bulb and epithelium was examined with immunohistochemistry. trkB-like immunoreactivity was seen in the fila olfactoria, epithelium and in vitro, in olfactory se nsory neurones. Since BDNF is expressed by olfactory sensory neurone t arget cells in the olfactory bulb, these data suggest that BDNF may ac t as a target derived neurotrophic factor in the primary olfactory sys tem.