• 1 January 1981
    • journal article
    • research article
    • Vol. 26  (1) , 68-82
Abstract
A collection of antibodies specific to different intermediate filament proteins were applied to frozen sections of adult rat brains. The relative distribution of these proteins was studied using double label immunofluorescence microscopy. Antibodies specific to each of the neurofilament triplet proteins (of approximate MW 68 K, 145 K and 200 K) stained exclusively neuronal structures. The distribution of these 3 antigens was in general identical, except that certain neurofilament populations such as those in the dendrites and cell bodies of pyramidal cells of the hippocampus and cerebral cortex, contained relatively little if any 200 K protein. Some neuron populations, such as the granule cells of the cerebrellar cortex, could not be visualized by neurofilament antibodies, indicating that neurofilaments may not be essential for function of all neurons in vitro. Antibodies to GFA [glial fibrillary acidic protein] and vimentin stained an entirely different population of processes, none of which stained with any of the neurofilament antibodies. Vimentin antibody stained sheath material around the brain, a monolayer of ependymal cell bodies lining the ventricles, fibrous material associated within the choroid plexes, walls of blood vessels and capillaries and the processes of cells in certain regions. GFA antibody stained a 2nd layer of sheath material under the vimentin layer and numerous processes visible throughout the brain. Some specific populations of GFA-positive processes stained also with vimentin. These included the processes of Golgi epithelial cells (Bergmann glial fibers), those of certain astrocytes in bundles of myelinated fibers. Some processes apparently derived from ependymal cells stained for both vimentin and GFA, while others could only be reliably visualized by vimentin alone. The results are discussed in terms of the morphological characteristics of the various cell types of the brain.