Fig. 1.

CREB phosphorylation at Ser¹³³in gerbil hippocampus after transient forebrain ischemia.A, Western blot of proteins isolated from post-ischemic hippocampal tissues at time 0–180 min after transient ischemia for 5 min. In the top panel, total CREB levels were not changed. However, pCREB levels were below the detection limit at the end of ischemia (0 min) but began to increase relative to controls and remained phosphorylated for at least 3 hr after reperfusion. The data in the bottom panel (bar graph) are presented as fold increase in pCREB, as determined by the optical density analysis of phosphorylated and total CREB levels. CREB phosphorylation was increased significantly from 5 to 30 min after reperfusion. Each column and bar represents mean ± SD (n = 7 for each recirculation period); *p < 0.05 versus control.B, Immunostaining for pCREB in the gerbil hippocampus after reperfusion for 15 min. pCREB was detected primarily in the nuclei of pyramidal cells, dentate granule cells, and neocortical neurons from 15 to 60 min after reperfusion. Left panel, Lower magnification image of the hippocampus. Scale bar, 500 μm.Middle panel, Higher magnification image of CA1 pyramidal neurons. Scale bar, 50 μm. Right panel, Absorption test to confirm the specificity of the anti-pCREB antibody.