The oligodendroglia cytoskeleton in health and disease

Oligodendrocytes have a high rate of synthetic activity and produce vast am ounts of myelin. The membrane production requires specific sorting and tran sport processes and structural support. in culture, oligodendrocytes extend flat membranous sheets containing an extensive cytoskeletal network of mic rotubules (MTs) and microfilaments (MFs). The microtubules participate in t he elaboration and stabilization of the myelin-containing cellular processe s and have an impact not only on the complex oligodendroglia architecture b ut also influence their functions. They participate in intracellular sortin g processes and the translocation of myelin basic protein (MBP) mRNAs to th e forming myelin sheath. The two major groups of neuronal microtubule-assoc iated proteins (MAPs), MAP2 and tau are expressed in oligodendrocytes and m ight be involved in the regulation of MT stability and organization. Myelin -specific proteins, such as MBP and 2',3'-cyclic nucleotide 3'-phosphohydro lase (CNP), interact with the cytoskeleton. Glial changes occur in a variet y of neurodegenerative diseases, and glial fibrillary tangles and glial cyt oplasmic inclusions (GCIs), containing abnormal microtubular structures whi ch stain positively for stress proteins and microtubule-associated proteins , are found in oligodendrocytes of the affected brains. The role of MTs and their associated proteins in oligodendrocytes during normal development an d pathological situtations is specifically emphasized in this review. (C) 2 000 Wiley-Liss, Inc.