Preservation of the entire population of normally transient ipsilaterally projecting retinal ganglion cells by neonatal lesions in the rat.

The number of ipsilaterally projecting retinal ganglion cells (IPRGCs) in developing normal rats and rats which received unilateral thalamic lesion and monocular enucleation at birth was studied using wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) as a retrograde neuronal marker. The results showed that the number of IPRGCs labelled in day-21 rats which received lesions at birth was comparable to the highest number of IPRGCs observed in normal rats on day 0 (day of birth). These results suggest that the entire population of IPRGCs which had their axons already grown in or near to their target structures on day 0 can be rescued by neonatal lesions.