Figure 5. NMDA induces CREB phosphorylation in vivo. Photomicrographs show retinal sections collected from postnatal rats 1 h, 2 h, and 1 day after intravitreal injection of BrdU-saline (Control) or BrdU-NMDA (NMDA). The retinal sections were labeled with antibodies against P-CREB or BrdU and counterstained with DAPI. Abbreviations: ganglion cell layer (GCL); inner plexiform layer (IPL); inner nuclear layer (INL); outer plexiform layer (OPL); outer nuclear layer (ONL). Arrow indicates P-CREB immunopositive cells. Asterisk (*) denotes P-CREB-BrdU coimmunolabeled cells. Pound sign (#) marks BrdU immunopositive cells. Calibration bar denotes 50 μm in middle left panel.