Restoration of vision III

Abstract
PREDICTING neuron death or survival after axonal injury is important in neurotrauma research. We now used in vivo confocal neuroimaging microscopy to repeatedly visualize retinal ganglion cells after optic nerve crush and studied their morphological alterations and ultimate fate. An intracollicular injection of a retrograde fluorescent tracer was made before or after optic nerve crush. Retinal ganglion cell sizes were then determined at different time points up to post-surgery day 75. Cell death was inevitable when soma swelling was fast and massive (86% above baseline or higher), but when it was slower and moderate (32% above baseline) long-term neuron survival could be predicted with high accuracy as early as post-operative day 5. Moderate swelling continued until day 15 (64%) and after about 3 weeks these cells started shrinking again, as a sign of recovery. We propose that moderate soma swelling is an adaptive rather than pathogenic posttraumatic reaction to axonal injury.