Fig. 4. Whole-brain FSE T2w MRIs show Mbnl1/2 genotype-dependent regional volume alterations.
a, c, e, g A montage of slices of extracted whole brains of representative 2-mo Mbnl1+/+/Mbnl2+/+ (wild-type control) Mbnl1−/−, Mbnl2−/−, and Mbnl1−/−/Mbnl2+/− mice that underwent in vivo 2D FSE T2w MRIs, respectively, are shown. b, d, f, h Show regions of interest (ROI) manually drawn and color-filled as described in the Methods. Only ROIs that are significantly different from the control Mbnl1+/+/Mbnl2+/+ brains are color-filled in the Mbnl1+/+/Mbnl2+/+, Mbnl1−/−, Mbnl2−/−, and Mbnl1−/−/Mbnl2+/− montages. Colored regions are white matter regions, which include the anterior commissure and corpus callosum/external capsule (yellow), and gray matter regions, which include the cerebellum (red), the hippocampus (green), and the hindbrain (pink). Calculated areas from the ROIs were multiplied by the image-slice thickness to generate ROI volumes shown in Figs. 5–7. The olfactory bulb was excluded in volume measurements. Slice positions were identified based on Bregma locations. The slice where the anterior commissure is connected between hemispheres approximates Bregma, which is defined as 0.0 mm. Going from rostral to caudal slice positions, boxes indicate structural landmarks that include Bregma (red box), the last slice containing hippocampal regions (green box), and the end of the brain (yellow box). Slice thickness = 0.5 mm. Scale bar = 1 mm.