P. Laeng et al., TRANSPLANTATION OF OLIGODENDROCYTE PROGENITOR CELLS INTO THE RAT RETINA - EXTENSIVE MYELINATION OF RETINAL GANGLION-CELL AXONS, Glia, 18(3), 1996, pp. 200-210
In most mammals, retinal ganglion cell axons are unmyelinated in the r
etina. The same axons become myelinated in the optic nerve. Various st
udies suggest that retinal ganglion cell axons are also in principle,
myelination competent intraretinally and that non-neuronal factors at
the retinal end of the optic nerve prevent the migration of oligodendr
ocyte progenitor cells into the retina. To test this hypothesis direct
ly, we injected oligodendrocyte progenitor cells into the retina of yo
ung postnatal rats. We observed massive myelination of ganglion cell a
xons in the retina I month after cell transplantation. Electron micros
copic analysis revealed that intraretinal segments of ganglion cell ax
ons were surrounded by central nervous system myelin sheaths with a no
rmal morphology. Our results thus provide direct evidence for the myel
ination competence of the intraretinal part of rat retinal ganglion ce
ll axons. (C) 1996 Wiley-Liss, Inc.