5′-Nucleotidase localization in the brains and spinal cords of adult normal and dysmyelinating mutant (shiverer) mice

Abstract

Immunocytochemical staining with the antibody against mouse liver 5′-nucleotidase revealed 5′-nucleotidase antigenicity in myelinated fibers in the brains and in myelinated fibers and some interfascicular oligodendroglia in the spinal cords of normal adult mice. Although the 5′-nucleotidase specific activity in adult shiverer mouse CNS tissue homogenates had been shown to be normal, immunocytochemical staining with anti-mouse-5′-nucleotidase could be demonstrated in CNS tissue sections from only 2 out of 10 of the mutant animals. In tissue from these animals the staining, which was relatively faint, was localized specifically to cell-bodies, usually arranged in rows, and to material oriented parallel to nerve fibers. This pattern of immunostaining with anti-5′-nucleotidase resembled the immunostaining with anti-carbonic anhydrase but not with anti-glial-fibrillary-acidic-protein. This suggested that the rows of cells were oligodendrocytes, not astrocytes, and that the material parallel to nerve fibers might consist of oligodendrocyte processes wrapped loosely around axons. The antibody against rat 5′-nucleotidase, as distinguished from mouse, immunostained only the blood vessels in the shiverer mouse CNS, a finding similar to a previous observation in the normal mouse CNS. From these findings it was inferred that the primary loci of 5′-nucleotidase in the shiverer mouse CNS were interfascicular oligodendrocytes, their processes, and blood vessels, and in the normal mouse CNS, the myelin in some tracts, the blood vessels, and some interfascicular oligodendrocytes.