Fig. 2.
Anesthesia increases phosphorylated cAMP-responsive element-binding (CREB) in the immature hippocampus after 24 h. The expression of CREB total and phosphorylated protein fractions was estimated by Western blotting in fresh hippocampal tissue obtained from P7 rat pups soon at 2 h or 24 h (at P8) postanesthesia or sham treatment. The protein levels were expressed as percentage change from sham controls after normalization to glyceraldehyde phosphate dehydrogenase (GAPDH). (A) Anesthesia caused a significant decrease in total CREB protein expression at 2 h (*P = 0.044, n = 6). (B) Anesthesia caused no change in total CREB expression at 24 h (P = 0.72, n = 7). (C) Anesthesia caused no change in the level of activated (phosphorylated) CREB protein in developing hippocampus at 2 h (P = 0.884, n = 10). (D) Anesthesia significantly increased the level of activated (phosphorylated) CREB protein in developing hippocampus at 24 h (**P = 0.002, n = 10). (E) Calculated ratio between phosphorylated and total CREB was significantly increased in anesthesia-treated animals compared with their respective controls at 24 h (*P = 0.025). GA = general anesthesia; P = postnatal day.