Immunological Distinction between Neurofilament and Glial Fibrillary Acidic Proteins by Mouse Antisera and Their Immunohistological Characterization (Part 1 of 2)

Antisera were raised in mice to the presumed protein subunits of the two types of 100 A filaments in nervous tissue, glial fibrillary acidic (GFA) protein and neurofilament (NF) protein. These antisera detect a pronounced antigenic distinction between these two proteins. Antiserum to GFA protein reacts only with astroglial cells and is therefore similar to antisera prepared in rabbits. Mouse antiserum to NF protein reacts with neurons and their processes known to be rich in 100 A filaments. Postsynaptic densities do not detectably react with anti-NF antiserum when assayed by the indirect immunoperoxidase method and studied at the electron microscopic level. The two antisera do not react with actin, myosin oe nervous system, NF protein is immunohistologically detectable at embryonic day 13 (the earliest stage tested). GFA protein is not detectable with this method during embryonal development but becomes apparent only at early postnatal ages. In several species (rabbit, rat, chicken, fish, turtle, and frog) anti-NF protein antiserum only reacts with neurons, and anti-GFA protein antiserum stains glia exclusively. On the surface of trypsin-dissociated, single liver cerebellar cells from 7-day-old mice, each antiserum detects antigenic specificities which are cross-reactive with its corresponding antigen.