Fig. 6

Astrogliosis of chronic CPZ increases coherence within CC. a-b: Coronal sections from naïve and 12 week CPZ mice perfused after final MRI and immunolabeled for GFAP to detect astrocytes. Coherence of astrocyte morphology was measured in a CC area (yellow rectangle) of relatively aligned anatomical structure. In the non-pathological CC of naïve mice, the astrocyte density is low and cell processes extend in many directions, resulting in close to isotropic coherence (a; red). After CPZ, astrocytes have a high density and align parallel to axons in the chronically demyelinated CC, so that the GFAP immunoreactivity exhibits anisotropic coherence (b, red). c-d: Color maps illustrating the orientation (c, inset) of the astrocyte cell bodies and processes in higher magnification images taken from the same sections as in A and B. In naïve mice, astrocyte cell bodies and processes exhibit diverse color encoding indicating orientation in many directions (c). After CPZ, astrocytes are aligned parallel to axons in the CC (green color orientation) and in the perpendicularly aligned cingulum (Cg) tract (magenta color orientation). e-g: Quantification of the coherence shows a significant increase in CPZ demyelinated mice (e) that does not recover during the 2 weeks on normal chow (f), and is not changed in iNSC transplant mice (f). In sections immunolabeled for MOG (g), the coherence for myelin is similar to that measured for astrocytes (f-g). Bar color reflects condition as chronic cuprizone followed by vehicle injection (black) or iNSC transplant (green). Data are mean values ± sem. Mouse numbers shown in Figs. 3 and 5, with comparison by t-test. Scale bars A, B shown in A = 100 μm; C, D shown in C = 100 μm