GLIAL-CELL ABNORMALITIES IN THE CNS OF THE CARBONIC ANHYDRASE-II DEFICIENT MUTANT MOUSE

The Car-2n/Car-2n mutant mouse is entirely lacking in carbonic anhydra se II (CA), which is normally found in myelin and glial cells in the C NS. CNS tissue from CA-deficient mutant mice was examined to see wheth er abnormalities could be detected which might help in understanding t he function(s) of CA in the normal brain. Analyses of myelin yields an d myelin proteins showed no differences between mutants and normal lit termates. To visualize the oligodendrocytes and astrocytes in tissue s ections, immunocytochemical staining was performed using antibodies ag ainst the Pi form of glutathione-S-transferase and glial-fibrillary ac idic protein, respectively. In both gray and white matter from the mut ants' brains the oligodendrocytes appeared to be shrinking and, possib ly, degenerating. Hypertrophy of astrocytes occurred in the white matt er, and the astrocytes in gray matter appeared swollen. It is suggeste d that imbalances in the HCO3-/CO2 ratios in various glial-cell compar tments may produce abnormal distributions of water and ions in the bra ins of the CAII-deficient mice.