Visualization of proteinaceous granules in the clear synaptic vesicles.

A method for demonstration of electron-dense particles within clear synaptic vesicles from various areas of the CNS as well as from neuromuscular junctions of rat is described. Electron-dense granules of 70-250 A were visible in the center of the synaptic vesicles, or in some cases excentrically situated and bound to the vesicular membrane. Digestion with proteolytic enzymes lead to a negative reaction, whereas treatment with hyaluronidase and neuraminidase, as well as the lipid extraction had no effect. Based on the obtained data, it may be assumed that this method manifests the proteinaceous structures.