Summary

Environmental Enrichment Rcompared to mice in standard housing conditions. Inspecific transcripts in brains of transgenic mice. parallel, we observe a significant elevation in the activ-ity of an Aβ-degrading protease, neprilysin (NEP) inIntroduction brain extracts from enriched mice compared to stan-dard-housed animals. Using high-density AffymetrixAlzheimer’s disease (AD), the major cause of adult-GeneChips microarray technologies, we show that, inonset dementia, is associated with progressive memory hippocampi of younger mice, the majority of transcripts that were significantly upregulated in enriched mice*Correspondence