Alzheimer's disease (AD) is the result of a progressive build-up of a specific protein (beta protein) in the brain parenchyma, in the form of amyloid deposits. Development. Amyloid deposits in AD are the result of genetic and environmental factors that alter the metabolism of the amyloid-beta precursor protein.
Amyloid accumulation in brain tissue leads to toxic phenomena translated into synaptic loss and, later on, into the formation of neurofribillary tangles and neuronal death. Conclusions. Synaptic loss is correlated to memory disorders characteristic of early stages of the disease, and neuronal loss with advanced dementia. This sequence of facts, known as "amyloid cascade", is supported by multiple genetic and experimental studies.