**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**.