beta-Amyloid precursor polypeptide in SAMP8 mice affects learning and memory

Senescence accelerated (SAMP8 [P8]) mice develop age related deficits in me mory and learning. We show that increased expression of amyloid precursor p rotein (APP) and its mRNA in the hippocampus are also age-related. Immunocy tochemical data suggest that a critical amount of APP expression may be nee ded to generate amyloid (A beta) protein plaques in the hippocampus. Defici ts in acquisition and retention test performance were alleviated by adminis tration of antibody to A beta protein into the cerebral ventricles. This re vel-sai of cognitive deficits provides a link between increased expression of both APP and A beta protein and learning and memory loss in these mice. (C) 2000 Published by Elsevier science Inc.