FIG. 5.

A model of developmental trajectories available to Müller-glia-derived neurons in mammals. During development (top panel), late retinal progenitor cells produce nascent Müller glia, which develop into mature Müller glia. For regeneration to occur (bottom panel), Müller glia must enter a general neurogenic state (top), which may bear a resemblance to their developmental state (dotted arrow and question mark). According to the protocol delivered, they seem to be capable primarily of producing bipolar/amacrine-like neurons (left path) or RGC/amacrine-like neurons (right path). Additional factors may be necessary to enable a true bipolar, amacrine, or RGC fate (bottom row).