Role of glial activation in neuroprotection of the retina

Abstract

AbstractThe effects of retinal injury on the neuronal and non‐neuronal cell population of the injured and the fellow‐uninjured retina were investigated in adult mice. Unilateral left eye retinal injury was induced by intraorbital optic nerve transection (IONT) or by laser‐induced ocular hypertension (OHT). Both retinas were prepared as wholemounts and immunostained with Brn3a, Iba‐1 and GFAP to identify, count and map the distribution of retinal ganglion cells (RGCs), microglia and astrocytes, respectively. OHSt was used to trace RGCs and to identify phagocytic microglia. By 2 wks after IONT or OHT, RGCs in the left retinas represented 20% of the original population. Following IONT, microglial cells in the left retinas increased with time from center to periphery and this response diminished with BDNF treatment, while in the fellow retinas phagocytic migroglial cells appeared at 3 days but their numbers were not modified with vehicle or BDNF. Following OHT there was a marked macro and microglial reactivity in both retinas. Thus, IONT and OHT induce changes in the macroglia and microglia of the injured and contralateral uninjured fellow retinas. The gliotic response in the fellow retinas could be immune related.