Age of cells populations in MS
* About Normal appearing white matter (NAWM), which are fully myelinated regions previously thought to be unaffected by MS, oligodendrocytes were present in normal numbers, but a couple of normal clusters of mature cells were nearly absent, showing that the present cells were born after the MS damage.
* Surviving mature oligodendrocytes contribute to remyelination. In animal models instead remyelination is made by newly born Oligodendrocytes, generated from newly recruited OPCs.
* Oligodendrocytes that appear morphologically normal in individuals affected by MS are affected by disease and are in an altered state.
* The pathology of MS lesions may be the tip of the iceberg of all cellular changes ongoing in the MS brain as a whole
* Oligodendrocytes in white matter from healthy individuals are as old as neurons. In MS, there is a much larger fraction of recently generated OPCs and oligodendrocytes than in unaffected individuals
* Oligodendocytes in shadow plaques, lesions thought to exhibit incomplete myelin repair, are as old as the patient and therefore could not have been generated from newly recruited OPCs.