Fig. 7

Model of pro-inflammatory cytokine IL-1β and anti-inflammatory cytokine IL-10 inducing Müller glia proliferation in light-damaged retinas. (A) Schematic depicting rod and cone photoreceptors (blue and brown, respectively), Müller glia (purple), and resting microglia (gray) in an undamaged retina. (B) Upon light damage, the resting microglia move from the locations in the plexiform layers to the outer retina where they become activated and begin phagocytosing dying rods and cones. The dying photoreceptors express TNFα. (C) The activated microglia express IL-1β and IL-10 in a dynamic fashion that signal the Müller glia to reprogram. (D) The reprogrammed Müller glia divide asymmetrically to produce a neuronal progenitor cell (NPC, green), which will continue to proliferate and differentiate into the missing retinal neurons.