Connectivity strength quantification of presynaptic input regions to SUB excitatory neurons. The CSI is the ratio of the SUB input neuron number in a subregion to the total starter neuron number in a brain. The input regions include the hippocampal CA1, CA2, and CA3 sublayers, as well as the SUB, postSUB, thalamus, RSC, Vis cortex, Aud cortex, SS cortex, TeA, Prh, Ect, LEC, and MEC. The regions showing statistical differences are shown in red text. A, WT young mice have significantly lower CSI values relative to 5xFAD young mice in the Vis cortex (p = 1.29 × 10−2). B, WT middle-age mice have significantly higher CSI values relative to 5xFAD middle-age mice in the CA1_py, CA1_or, CA1_rad, MS-DB, Vis cortex, and Aud cortex (p = 1.2 × 10−4, p = 4.46 × 10−2, p = 8.78 × 10−3, p = 3.33 × 10−3, p = 1.29 × 10−2, and p = 1.38 × 10−2, respectively). C, WT young mice have significantly higher CSI values relative to WT middle-age mice in the SUB and MS-DB (p = 4.66 × 10−2, and p = 2.74 × 10−2, respectively). WT middle-age mice have significantly higher CSI values relative to WT young mice in the CA1_rad (p = 8.78 × 10−3). D, 5xFAD young mice have significantly higher CSI values relative to 5xFAD middle-age mice in the CA1_py, CA2_py, MS-DB, RSC, Vis cortex, Aud cortex, and TeA (p = 1 × 10−5, p = 5.6 × 10−4, p = 4.03 × 10−3, p = 4.46 × 10−2, p = 1.2 × 10−3, p = 8.1 × 10−4, and p = 6.45 × 10−3, respectively). E, CSI comparisons of example regions across four groups of mice. Representative regions include the MS-DB, CA1_py, SUB, Vis Cortex, and Aud Cortex. The mouse numbers for each group are WT young, n = 8; WT middle-age, n = 10; 5xFAD young, n = 10; and 5xFAD middle-age, n = 12. The statistical test is the Wilcoxon rank-sum test. The p values are adjusted with the FDR Benjamini–Hochberg approach (desired FDR = 0.05). All data are represented with mean ± SEM. Statistical significances are denoted by *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001, and ****p ≤ 0.0001. See also Tables 3 and 4.
