Dementias
Diseases that involve the hippocampus and associated cortices present with cognitive changes
With time these progress to dementia, as occurs with Alzheimer disease.
Alzheimer's Disease
NDD caused by the accumulation of Amyloid β plaques and tau tangles, leading to neuronal damage.
- Most common cause of dementia in older adults
- Especially of intellectuals
- Aβ occurs when a normal protein -- amyloid precursor protein (APP) -- is cleaved by the enzymes β-amyloid-converting-enzyme (BACE) and gamma-secretase
- The gene coding for APP is found on chromosome 21 -- Increased risk in Trisomy 21
- Apolipoprotein E isoforms can promote Aβ generation
- Tau
- A microtubule-associated structural protein present in axons
- Mechanisms:
- The stabilizing function is lost
- Aggregation causes cellular stress
- Inflammation and activation of the innate immune system due to Aβ and tau