As shown in Figure 8, the level of BDNF decreased significantly in the control + IE group compared with those in the control + SE group, suggesting IE impaired cognitive impairment by decreasing BDNF level in the hippocampus (F(5, 24) = 8.833, P < 0.001, Figure 8A) but not in the prefrontal cortex (F(5, 24) = 0.575, P = 0.719, Figure 8B). This evidence concerns the gene BDNF and Cognitive impairment.