Glial fibrillary acidic protein (GFAP; blue) immunolabeling in vertical sections of 7-day-lesioned chick retinas counterstained with propidium iodide (red).

<p>(A–C) Vertical sections of chick retina were counterstained with propidium iodide (red) to facilitate visualization of the nuclear layers. In order to validate the focal lesion model, GFAP (blue) immunolabeling was conducted. We detected typical intense GFAP labeling, representing the reactive gliosis process, which decreased toward the penumbra and adjacent areas (n = 3, 3–5 samples per retina). (D) With the use of a pixel analysis, quantification of the optical density along the focus, penumbra, and adjacent areas was possible. The labels indicate the approximate location of the outer nuclear layer (onl), the outer plexiform layer (opl), the inner nuclear layer (inl), the inner plexiform layer (ipl), the ganglion cell layer (gcl), and the nerve fiber layer (nfl). Scale bar: 60 µm.G.