Microglial transplantation increases amyloid-β clearance in Alzheimer model rats

Immunization with amyloid-β (Aβ) peptides, a therapeutic approach in Alzheimer’s disease (AD), reduces brain Aβ, and microglial Aβ phagocytosis has been proposed as an Aβ-lowering mechanism. We transplanted rat microglia into the rat lateral ventricle just after intra-hippocampal Aβ injection, and then investigated the contribution of exogenous microglia to Aβ clearance. Migration of exogenous microglia from the lateral ventricle to Aβ plaque was detected by magnetic resonance imaging and histochemical analysis, and the clearance of Aβ was increased by transplantation. These results suggest the possible usefulness of exogenous microglia to the therapeutic approach in AD.