Figure 3

Evaluation of changes in the optic nerve. (A) H&E-stained longitudinal optic nerve sections of EAE animals exhibited signs of optic neuritis indicated by cell clustering and disorganization (arrowheads) compared to a regular alignment of cells in the CO (arrows). (B) The infiltration score (from 0 for no infiltration to 4 for massive infiltration) positively correlated with the EAE score (P< 0.0001, r = 0.9824). CO mice (blue circles) had no clinical symptoms and infiltration while EAE mice (green circles) had both clinical symptoms and infiltration of cell clustering in the optic nerve (n = 4 eyes/group). (C) Luxol fast blue staining in longitudinal optic nerve sections of EAE animals revealed signs of demyelination indicated by white areas in the optic nerve (arrowheads). In CO nerves the myelin sheaths were uniformly stained. (D) The demyelination score (from 0 for no demyelination to 2 for strong demyelination) was positively correlated with the EAE score (P = 0.0053, r = 0.8328). CO animals displayed no signs of clinical EAE while in contrast all EAE mice had a clinical EAE score as well as mild to severe demyelination in the optic nerve (n = 5 eyes/group). Scale bars: 50 μm. CO, control; EAE, experimental autoimmune encephalomyelitis; H&E, hematoxylin and eosin stain.