Colocalization of CRY1 and neuronal-activity markers in the same 300-nm-thick retina slice from a magnetically orienting garden warbler. (a) Example of Western blot analysis confirming specificity of the antibody and quantification of c-Fos expression in the ganglion cell layer. For definition of intensity index, see Materials and Methods. Dashed line indicates unspecific background level of expression. (b and c) Immunohistochemical double labeling of CRY1 (cytosolic) with the neuronal-activity markers c-Fos (b; cytosolic and nucleic) and ZENK (c; exclusively nucleic; only the ganglion cell layer is shown) reveal that CRYs are found in night-active ganglion cells and in large displaced ganglion cells of the INL (arrows). (Scale bar, 40 μm.) GCL, ganglion cell layer; IPL, inner plexiform layer; OPL, outer plexiform layer; ONL, outer nuclear layer.
