Decrease in oligodendrocyte carbonic anhydrase activity preceding myelin degeneration in cuprizone induced demyelination

Both immunohistochemical and biochemical evidence is presented to show for the first time that carbonic anhydrase II (CA II) activity falls in the brain of mice in cuprizone (bis(cyclohexanone)oxalyldihydrazone) induced demyelination well before demyelination develops. This fall began during the first week, whereas the first signs of myelin degeneration induced by cuprizone did not appear until 3 weeks and demyelination in the superior cerebellar peduncle in the mouse took 6–8 weeks to develop. The findings suggest that oligodendrocyte CA II activity is essential either for the survival of oligodendrocytes or for the maintenance of central myelin.