Figure 6

Linear PC Scores are modeled by Housing and GCRsim. (a) Loadings for features in the Linear PCA. Scores greater than |0.45| were used for interpretation of the PC. (b) PC1–Social exploration measures and B cells percentage from cardiac blood loaded strongly positively, while monocyte percentage from cardiac blood loaded strongly negatively on PC1. Two-way ANCOVA analysis had the best model fit for PC1. There was a significant main effect of housing (F(2,33) = (5.816, p = 0.007, η² = 0.261) and GCRsim (F(1,33) = 6.694, p = 0.014, η² = 0.169) on PC1. SI stress increased PC1 score compared to group housing (mean diff 1.155, 95%CΙ (0.294 to 2.015), p = 0.006). Sham irradiated animals scored higher on PC1 than 50 cGy exposed animals (mean diff 0.967, 95%CI (0.207 to 1.728), p = 0.014). (c) PC3- RAWM average errors and NOR percent time with the novel object loaded strongly positively. Two-way ANCOVA analysis including percent monocytes in early blood as a covariate had the best model fit for PC3. There was a significant interaction between GCRsim and housing condition (F(2,33) = 4.827, p = 0.014, η² = 0.226). Compared to shams, the 50 cGy exposed mice scored higher in group housing (mean diff 0.906 (95%CI (0.015 to 1.797), p = 0.047) and lower in SI housing (mean diff − 0.948, 95%CI (− 1.890 to − 0.007), p = 0.048). Within all sham exposed animals, SI animals scored higher than both SI + HU (mean diff 2.496, 95%C (1.272 to 3.720), p < 0.001) and group housed animals (mean diff 1.276, 95%C (0.212 to 2.341), p = 0.014). Sham group housed males scored higher than SI + HU animals (mean diff 1.220, 95%C (0.019 to 2.420), p = 0.045). Within all 50 cGy animals, group housed scored higher than SI + HU animals (mean diff 2.180, 95%CΙ (0.482 to 3.878), p = 0.008). Males n = 9 0 cGy group, 0 cGy SI; n = 8 50 cGy group; n = 7 50 cGy SI; n = 5 0 cGy SI + HU; n = 2 50 cGy SI + HU. *p < 0.05 **p < 0.01, ***p < 0.001.