English: Confocal microscopy imaging of rat retinal sections immunolabeled for glial fibrillary acidic protein (GFAP) reveals distinct morphological changes in Müller cell processes. In normal retinas on the left, GFAP expression is predominantly localized to the innermost layers, namely the nerve fiber layer and the ganglion cell layer (GCL). However, on the right, there is a marked increase in GFAP-positive fibers, indicating pronounced hypertrophy and thickening of Müller cell processes. These hypertrophic processes extended through the inner nuclear layer (INL) and outer nuclear layer (ONL), strongly indicative of retinal gliosis (Nuclei, stained with DAPI, appear blue under microscopy).