Ouabain-induced retinal degeneration results in a robust accumulation of responding immune cells. Images show cryosections from undamaged (control, A, C) and ouabain-damaged retinas at 3 days post-injection (3 dpi, B, D). A ZPR1 (green), PKC-α (Red), and DAPI (blue) were used to label cones of the outer retina, bipolar neurons of the inner retina, and all nuclei, respectively, in undamaged retinas. B Images of damaged retinas sampled at 3 dpi; inner retinal neurons have been destroyed (note the absence of PKC-α staining and absence of DAPI+ layer corresponding to the ganglion cell layer; GCL), but photoreceptors are spared (ZPR1, green). C Ramified microglia, labeled by L-plastin (magenta), are present in undamaged retinas, along with radially patterned Müller glia (ZRF1, green). D Müller glia (green) are spared from the ouabain-induced lesion. A large number of immune cells (magenta) responding to the lesion are present in the damaged retina, primarily localized to the region of neuronal cell death (inner retina), although some appear to be recruited from regions apical to the retina (arrows). DAPI+ nuclei in the inner retina visible in B can be identified as immune cells and Müller glia. Scale bar in A, applies to all images, = 20 μm. ONL = outer nuclear layer, INL = inner nuclear layer, GCL = ganglion cell layer