Abbreviations: BBB, blood-brain barrier; CNS, central nervous system; CSF, cerebrospinal fluid; CSPGs, chondroitin sulfate proteoglycans; EAE, experimental autoimmune encephalomyelitis; ECM, extracellular matrix; GAG, glycosaminoglycans; HMW hyaluronan, high-molecular weight hyaluronan; LMW hyaluronan, low-molecular weight hyaluronan; MBP, myelin basic protein; MMP, matrix metalloproteinase; MS, multiple sclerosis; MT-MMP, membrane-type matrix metalloproteinase; NAWM, normal appearing white matter; OPC, oligodendrocyte progenitor cell; TIMP, tissue inhibitor of metalloproteinase; TME, Theiler's murine encephalomyelitis.