Tn. Jelsma et al., DIFFERENT FORMS OF THE NEUROTROPHIN RECEPTOR TRKB MESSENGER-RNA PREDOMINATE IN RAT RETINA AND OPTIC-NERVE, Journal of neurobiology, 24(9), 1993, pp. 1207-1214
The expression of TrkB mRNAs was investigated in rat retina and optic
nerve. A 11.5 kb transcript that encodes full-length TRKB was found to
predominate in Northern blots of retinal RNA. By in situ hybridizatio
n, this trkB expression was concentrated in the ganglion cell and inne
r nuclear layers. Furthermore, an antibody to the full-length TRKB imm
unostained retinal ganglion cells and their axons. In contrast, Northe
rn blots of optic nerve RNA showed a prominent 9.5 kb band that encode
d a form of the TRKB receptor lacking the tyrosine kinase domain. This
species was also detected in both the sciatic nerve and cultured astr
ocytes and C6 glioma cells. These results suggest that neurons express
the full-length TRKB containing the tyrosine kinase domain, while non
-neuronal cells express the truncated form of the receptor. These two
classes of TRKB may mediate different neurotrophic actions in the reti
na and optic nerve. (C) 1993 John Wiley & Sons, Inc.