Viability of retinal ganglion cells after optic nerve crush in adult rats.

The response of retinal ganglion cells to optic nerve crush was examined in the hooded rat. Intracranial nerve crush produces a transient shrinkage of the retinal ganglion cells during the first several weeks postoperatively but partial recovery of cell size then appears to occur. This transient response is considered to be a direct response to axotomy. Retrograde transport of horseradish peroxidase (HRP) is clearly demonstrated at 2 weeks postoperatively. Transport of newly synthesized protein progressively decreases over the first 2 postoperative months. The ganglion cell therefore retains viability for at least the first few weeks after axotomy. Loss of 60% of the neurons in the ganglion cell layer occurs between 3 and 7 months postoperatively. This late occurring retrograde response is considered to result at least in part from loss of sustaining trophic influences rather than as a direct result of the lesion.