Sections Of CNS Research Articles

Myelin-associated glycoprotein (MAG) distribution in human central nervous tissue studied immunocytochemically with monoclonal antibody

Recent biochemical data show that myelin-associated glycoprotein (MAG) is the antigen for a monoclonal antibody found in sera of patients with IgM paraproteinemia and neuropathy (Braun et al. 1982). Immunoreactivity of this antibody with CNS has not been described. To study this, monoclonal anti-MAG was used in the avidin-biotin-peroxidase complex method (Hsu et al. 1981) to immunostain paraffin and epon sections of human CNS. Well characterized polyclonal MAG antiserum (Quarles et al. 1981) was employed in comparison tests. In paraffin sections of developing CNS, both monoclonal and polyclonal MAG antisera stained oligodendroglia and myelin. In adult CNS, periaxonal regions of myelin sheaths were immunostained in paraffin sections and semithin epon sections treated with monoclonal and polyclonal anti-MAG. In electron-microscopic experiments that included milder pretreatment of epon thin sections and more precise reaction product localization, entire thicknesses of myelin sheaths were immunostained. Thus.

G D3 ganglioside is a glycolipid characteristic of immature neuroectodermal cells

Biochemical studies have indicated that the disialoganglioside, GD3, is a major glycolipid component of the immature vertebrate CNS, but a minor element within the mature CNS. We have investigated its cellular localization in rat CNS by immunofluorescence using a mouse monoclonal antibody that recognizes GD3. In tissue sections of postnatal CNS, the antibody bound to cells in several areas known to contain immature neuroectodermal populations: the subventricular zone beneath the lateral ventricle, the external germinative layer of the cerebellar cortex, and the dentate gyrus of the hippocampus. GD3-containing cells were also found in developing white matter of the forebrain and cerebellar folia. Using a double-label immunofluorescence method, we found that the GD3-positive white matter cells did not express the astrocytic marker, glial fibrillary acidic protein. In adult rat CNS, we could not detect antibody binding to neurons or glia. Scattered GD3-positive cells were apparent in the adult subventricular zone. Our results indicate that GD3 ganglioside is a membrane component characteristically expressed in the rat CNS by neuroectodermal stem cells, both neuronal and glial precursors.

Simultaneous visualization of nuclear yellow and iron—dextran complex for demonstration of branched neurons by retrograde axonal transport

Retrogradely transported iron-dextran complex and Nuclear yellow could be demonstrated simultaneously on the same sections of rat CNS. Using combined bright-field and ultraviolet illuminations, double labeled neurons were observed. They exhibited a fluorescent nucleus and cytoplasmic Prussian blue granules. Thus, the combination of these two tracers appeared to be a convenient method for the anatomical demonstration of collaterals.

On the histochemistry of N-acetyl-β-D-glucosaminidase in rat central nervous system

The optimal conditions for histochemical demonstration of NAG activity in the cerebrum, diencephalon, midbrain, cerebellum, medulla oblangata, and spinal cord were studied in a series of 37 Wistar rats of either sex. The following more important results were obtained: Each CNS zone required a definite methodlogical approach. Optimal fixation for most structures was achieved after 2 h treatment with formol-calcium and subsequent immersion of tissue blocks in formol-calcium 0,88 M saccharose. By this fixation technique it was possible to preserve high enzyme activity and good tissue structure. Only for the large pyramidal cells of the cerebral cortex the method of Holt provided optimal fixation. Formol-calcium-saccharose mixture and pure 0,88 M saccharose produced the opposide osmotic effect on nervous tissue previously fixed with formol-calcium: the former induced tissue shrinkage, the latter edema. The use of hexazonium p-rosaniline coupler prompted preliminary alcohol treatment of sections and introduction of 0.1 M acetate buffer in the incubation solution. Acetate buffer concentrations lower than 0.2 M diminished the diffuse cytoplasmic coloration and permitted a clear-cut demonstration of the lysosomal reaction. Ample information on the distribution of NAG activity in the CNS was obtained by using fast garnet GBC coupler and 0.1 M citrate buffer. Manganese chloride in a 0.2 mM concentration activates the reaction. The distribution of NAG reaction product in the cells of the different sections of the CNS was studied. The distribution of NAG reaction product in the cells of the different sections of the CNS was studied. The neurons, glial cells, and blood vessels showed positive reaction. Strongest activity was reported for the neurons of the supraoptic and paraventricular necleus, the epithelial cells of the chorioid plexus, nucleus ruber of the mesencephalon, and the vascular wall pericytes.