Contribution of Microglia-Mediated Neuroinflammation to Retinal Degenerative Diseases

Figure 1

Schematic representation of the major retinal cell types and their organization in the retina. The outermost part of the retina is the retinal pigment epithelium (RPE), which consists of a monolayer of cuboid, pigmented cells between the photoreceptors and the choroid. The retina is divided into three laminar layers: the outer nuclear layer (ONL), the inner nuclear layer (INL), and the ganglion cell layer (GCL). The nuclei of rod and cone photoreceptors are located in the ONL. The INL comprises the nuclei of the bipolar, horizontal, and amacrine cells. Cell bodies of the retinal ganglion cells are present in the GCL, and their axons form the nerve fiber layer (NFL), just beneath the GCL. Synapses between photoreceptors and interneurons are located in the outer plexiform layer (OPL) and interneurons synapse with RGC in the inner plexiform layer (IPL). Müller cells span all retinal layers. Microglia are mainly found in IPL and GCL, whereas astrocytes are located near the NFL.