Alzheimer’s disease (AD) is characterized by progressive pathological
changes in the brain, including accumulation of protein aggregates such as amyloid
plaques and neurofibrillary tangles (NFTs). Deposition of these proteins leads to
widespread neuronal loss and subsequent cognitive decline. AD-associated pathology
also develops in individuals with Down syndrome (DS) and is generally found to
precede onset of dementia symptoms. In this chapter, we discuss progressive
development of AD pathology, including plaques, NFTs, synaptic dysfunction, neuronal
loss, and brain atrophy. Furthermore, we examine similarities and differences in these
pathologies between AD and AD/DS. Finally, we review several genetic factors that
may contribute to the development of AD.
Keywords: Amyloid plaques, Down syndrome, neurofibrillary tangles,
neurodegeneration, tau, trisomy 21.