Embryonic retinal grafts have a beneficial effect on the damaged host retina

The adult rat retina was evaluated following surgical lesion and after transplantation of embryonic day 15 (E15) retinal tissue. While a surgical incision caused degeneration and ganglion cell death peripheral to lesion site, the addition of an embryonic retinal implant to the lesion site resulted in a reduction of this degenerative response. In addition, the embryonic graft also exerted a stimulatory effect in the central direction from the lesion site, as increases in layer thicknesses were seen. We speculate that putative diffusable factor(s) may mediate these effects.