ABSTRACT
The historical controversy concerning retinal microglia and their origin did not significantly differ from that in other areas of the brain, although the presence of microglia in the various retinal layers became accepted relatively late. Microglia form a regular mosaic across the entire retina, although the exact distribution is species specific. The advent of monoclonal antibody techniques have decisively contributed to a better characterisation of the brain and retinal microglia. Microglia in the adult retina may also participate in synaptic remodelling, based on the fact that they accumulate in both PL, where retinal neurons make synaptic contacts, but are excluded from nuclear layers devoid of synapses. Inherited neurodegenerative diseases are characterised by progressive disappearance of neurons due to either intrinsic metabolic deficits or malfunctioning within neuronal networks. The microglia-derived signals which induce PCD are either oxidants or stimulators of oxidative metabolism.
