PSEN1 and Alzheimer disease: Compared with the wild-type mice, the immuno-bands were larger and denser in the APP/PS1 AD mice (Figure 2B), and IOD of the immuno-bands was significantly increased (Figure 2C, p = 0.002) [F(3,18) = 6.384, p = 0.004, ANOVA], indicating the increased expression of mGluR2.