RGC degenerations. A neural substrate for reversing glaucomatous damage?

The demonstration of retinal ganglion cell (RGC) dendritic remodelling and pruning in glaucoma raises the possibility that this could provide a neural substrate for the recovery of retinal ganglion cells. The associated reduction in the size of the retinal ganglion cell receptive field can arise as a result of the loss of dendrites but also due to the loss of synaptic connections. Since RGCs appear to maintain their central neural connections during the early stages of this degenerative process, the creation of conditions for the regrowth of RGC could allow the establishment of novel connections within the inner plexiform layer and the recovery of visual sensitivity. There is compelling evidence that the perineuronal environment within the retinal ganglion cell layer requires disruption as a first step to the promotion of dendritic plasticity and regrowth in the mature retina. I will discuss how that might be achieved using the rat glaucoma model as an example. In particular, I will address technical challenges that must overcome if we are to provide convincing data that RGCs have recovered in experimental glaucoma.