Intraocular transplantation of cell layers derived from neonatal rat retina

The goal of this study was to determine whether cell layers derived from either the inner or outer regions of the neonatal rat retina had the capacity to grow and differentiate when transplanted into the adult retina of the same species and, if so, whether there would be differences between the grafts originated from the two different cell populations. Two different tracers were used to label donor cells and to identify them following transplantation. Firstly, at postnatal day (PND) 2, the pups received bilateral injections of rhodamine-labeled microspheres in the superior colliculus in order to label retrogradely the retinal ganglion cells. From the day of birth until the day of sacrifice (PND 4), the donors received daily injections of [3H]thymidine to label the nuclei of dividing cells. At PND 4 the animals were sacrificed and the retinas isolated. Following brief enzymatic treatment, the inner and outer retinal regions were separated from each other using filter membranes. Cells derived from each of the two moieties were transplanted separately into the eyes of adult host animals of the same strain. After survival times ranging from 3 to 44 days, the host eyes were enucleated and prepared for examination using both light and electron microscopic methods. Both retinal regions gave viable transplants. Unexpectedly, the transplants derived from the inner zone of the retina survived better than those derived from the outer zone, despite the fact that the highest number of undifferentiated and mitotically active cells occurred in the latter.(ABSTRACT TRUNCATED AT 250 WORDS)