In a two-photon imaging study using the APPPS1 mouse model of AD, a model of amyloidopathy expressing human APP with the Swedish mutation and human mutated presenilin (PS)1 (L166P mutation), microglial motility was impaired in the presence of Aβ plaques when a focal lesion was induced by a laser, with reduced extension of processes towards the lesion. This evidence concerns the gene APP and Alzheimer disease.