Figure 2.

Reduced white matter volume in the prefrontal cortex and corpus callosum in germ-free piglets at 16 days of age. (A) Representative coronal planes of MRI images and 3D segmentations illustrating traced regions of interest: PFCWM (red), CC-Genu (green), CC-Body (cyan), and CC-Splenium (magenta). PFCWM, prefrontal subcortical white matter; CC, corpus callosum. (B) 3D cartoon of and 3D segmentation of PFCWM (red) and CC-whole (yellow). Black arrows indicate subregions of the CC. White arrows demarcate the CC-genu and CC-splenium. (C) Quantification of white matter volumes (mm³) in control (C) and germ-free (GF) piglets. Individual male and female animals are marked by orange triangles and circles, respectively. Data expressed as mean ± SEM, n = 4–6 animals/group. ****p < 0.0001, two-way ANOVA; *p < 0.05, **p < 0.01, unpaired student’s t-test P16-C vs. P16-GF.