[Histochemical representation of acetylcholinesterase in Alzheimer's disease].

Senile plaques in the cerebral neocortex, entorhinal cortex and hippocampus are reactive for Acetylcholinesterase (AChE). The same types of plaques are observed, as with immunostains for beta-protein, including the very simple ones, consisting nearly exclusively of loose deposits of beta-protein. If there are many plaques, the normal network of AChE-positive axons disappears. Explanations for both, the apparent shift of AChE from the axons to the plaques on the one hand and the very early development of AChE positive deposits during the plaque development on the other hand are sought.