Figure 4. P-CREB blockade decreases NMDA-mediated cell proliferation. A-C: Photomicrographs show DAPI stained cells incubated in the absence (A) or presence (B) of 25 μM CREB inhibitor, for 48 h and cultured in fresh medium for additional 48 h. C: Graph shows quantification of control and CREB inhibitor treated cells. Data represent mean±SEM of cells counted on five nonoverlapping fields in three experiments. Asterisk (*) denotes p<0.05 compared to control. D-F: Photomicrographs show DAPI and TUNEL stained control (D) and CREB inhibitor (E) treated cells. F: Graph shows quantification of TUNEL positive cells in control, 100 μM NMDA, NMDA plus 25 μM CREB inhibitor or CREB inhibitor treated cells. Data are represented as in C. G-I: Photomicrographs show DAPI, BrdU, and P-CREB stained cells that were untreated (G) or treated with 100 μM NMDA (H) or NMDA plus CREB inhibitor (I). Calibration bar equals 50 μm in A, D, and I.