Figure 3. NMDA induces CREB phosphorylation in retinal progenitors. A-C: Photomicrographs show P-CREB labeled cells counterstained with DAPI after no treatment (A) and 100 μM NMDA (B), or glutamate (C). D: Graph shows the quantification of nestin-P-CREB double-positive cells in control, NMDA, or glutamate-treated cultures. Data represent mean±SEM of 100 cells counted on nonoverlapping fields in three experiments. Double asterisks (**) indicate p<0.05 compared to control. E: Graph shows the percentage of P-CREB positive cells after no treatment, 100 μM NMDA, or 100 μM NMDA plus 50 μM MK801. Data represent the percentage of P-CREB positive cells with respect to total number of cells counted on five nonoverlapping fields. F-G: Photomicrographs show NR1-P-CREB (F) and nestin-P-CREB double-labeled cells (G) counterstained with DAPI. Calibration bar equals 100 μm in A-C and 20 μm in F.