Borroni_1989_Exs_57_59

By use of an antiserum raised against presynaptic plasma membrane purified from the purely cholinergic electromotor system of Torpedo marmorata we have been able to identify a group of antigenically-related minor gangliosides (collectively designated Chol-1) that appear to be exclusively localized on cholinergic neurons. The cholinergic-specificity of these antigens has been shown by the following findings: a) The anti-Chol-1 antiserum induces a selective complement-mediated lysis of the cholinergic subpopulation of mammalian brain synaptosomes; b) Section of the fimbria, which causes a massive degeneration of cholinergic terminals in the hippocampus, leads to a concomitant depletion of the level of the Chol-1 gangliosides in the hippocampus; c) The anti-Chol-1 serum can be used to immunostain cholinergic elements in the central and peripheral nervous systems of the rat. The discovery of a cell surface cholinergic-specific antigen has provided a new and effective tool with which to study the cholinergic neuron. For instance, we have immuno-isolated cholinergic synaptosomes from rat cortex and used this preparation to study transmitter coexistence. Our results indicate that approximately 75% of the cortical cholinergic neurons also express the neuropeptide VIP. Furthermore, we are investigating the expression of Chol-1 in patients affected by diseases such as ALS which primarily involve central cholinergic neurons.