To evaluate whether Smad7 is involved in the occurrence of cognitive impairment after anesthesia and surgery by regulating the TGF-β1-related signaling pathway, we detected the protein expression of Smad2/3, Smad4 and phosphorylated Smad2/3 in the hippocampus in wild-type mice and Smad7−/− mice. Here, SMAD4 is linked to Cognitive impairment.