Fig. 3.

Neuritic pathology in a mouse model of amyloidosis. Electron micrograph of neuropil in the vicinity of a fibrillar plaque (not shown) of an APPPS1 mouse. Dystrophic axons (labeled “Axon”) appear enlarged and filled with electron-dense membranous material. Several synaptic densities are marked with arrows. Note that most synapses originate from unaltered synaptic boutons, while only a single synapse originates from the dystrophic axon (double arrow, far right), which may reflects spine loss as a result of presynaptic failure