Figure 1. Tissue plasminogen activator immunoreactivity in the visual cortex of the Long Evans rat. A, B, D, F, and H: Low magnification photomicrographs shows the visual cortices of rats aged postnatal week 1 (PW1), PW3, PW5, PW7, and PW14, respectively. Photomicrographs were taken in the transitional region between monocular and binocular visual cortex. Note that no tissue plasminogen activator (tPA) is stained in the visual cortex at PW1 (A), although tPA-positive cells are prominent in layer II-III at later ages. C, E, G, and I: Higher magnification photomicrographs shows tPA staining in layer V-VI at the same ages. Note the faint apical dendritic labeling seen at PW3, PW5, and PW7. The scale bar in A represents 100 μm and also refers to B, D, F, and H; the scale bar in C represents 20 μm and also refers to E, G and I.