Microtubules are most common at the margins of the cell, in the occasional cell process and in the cytoplasmic loops around myelin sheaths. Lamellar dense bodies, typical of oligodendrocytes, are also present [5]. The nucleus is usually ovoid, but slight lobation is not uncommon. The nucleochromatin stains heavily and contains clumps of denser heterochromatin; the whole structure is sometimes difficult to discern from the background cytoplasm. Desmosomes and gap junctions occur between interfascicular oligodendrocytes [5].