Alzheimer's Flashcards
What happens to the brain mass during aging?
brain volume decreases, frontal lobe and hippocampus shrink more than other areas.
What happens to the cortical density during aging?
There is a decrease in synaptic connections, the wrinkled outer layer thins (contains neuronal cell bodies)
Decrease in what chemical are there in the neurotransmitter system during aging?
decrease in Ach, dopamine and serotonin
What happens in the white matter during aging?
- deterioration of fibre connections
- loss of small little myelin that are later developed
- structural integrity changes
What happens with the grey matter during aging?
- cortical thinning
- shrinking of neurons
What is semantic memory?
Knowledge about facts
What is episodic memory?
Memory of experiences
What are the positive features of AD?
- dystrophic neurites
- microgliosis
- astrogliosis
- neurofibrillary tangles (accumulaten of protein TAU)
What are the negative features of AD?
- loss of neurons
- loss of neuropil
- loss of synaptic elements
- reduced grey matter volume
- reduced structural integrity
What more characteristics of AD are there?
- neuroinflammation
- lipid dysbalance
- BBB dysruption
- cognitive decline
- presence Hirano bodies
What happens in neuroinflammation?
- mainly driven by amyloid plaques and neurofibrillary tangles
- microglia are activated by PAMPs or DAMPs
- astrocytes release cytokines, ILs and nitric oxide
- Chronic exposure to these inflammatory mediators cause neurodegeneration
What happens in the BBB dysruption?
- breakdown BB causes toxic molecules, cell parasites or microbial agents to enter the brain
- Immune response to this causes neurodegeneration
- Microbleeds cause release of Fe2+, inflammation
What lipids are disbalanced?
-cholesterol
- Sphingolipids
- phospholipids
- gangliosides
What are hirano bodies?
intracellular aggregates of actin and actin-associated proteins
What happens in cognitive decline?
- restriction daily routing
- episodic and semantic memory deficits
- deficits in executive function
What are the most important symptoms of early onset AD?
- vision or dept perception problem
- increasingly poor judgement
- withdrawal work and social situations
- changes in mood and personality
- losing track of date, time, where you are and how you got there
What are some riskfactors of AD?
- aging
- carrier of APOE4
- familial history of mutations
- lifestyle
- obesity and hypercholesterolemia
- cerebrovascular diseases and head trauma.
What are preventive factors of AD?
- physical activity
- Vitamin E can reduce AB aggregation
- mediterranean diet
- cognitive stimulating activities
There is no treatment yet for AD, what are the symptomatic treatments of AD?
- cholisterinase inhibitors, such as donepezil(prevents acetylcholine to be degraded, this is essential for processing memory and learning)
- NMDA-antagonists, such as memantine, blocks NMDA receptors and prevents glutamate from entering the cell
- antiAB antibodies, for the removal of brain amyloid B peptide.
What are the characteristics of early onset AD?
- family heritage
- genetic causes, chromosome 1,14 and 21
- people with down syndrome have a higher chance
- 5% of AD patients
- younger than 65 years old. around 40 usually
What are the characteristics of late onset AD?
- no hereditics
- 95% of AD patients
- might have genetic causes
- crucial role of environmental factors
- later than 65 yo
What are the 3 single-gene mutations that are associated with early-onset alzheimer’s disease?
- presenilin 1 (PSEN1)on chromosome 14
- presenilin 2 (PSEN2) on chromosome 1
- amyloid precursor protein on chromosome 21
What are the functions of the APOE alleles?
- APOE 2 lowers the risk of AD
- APOE 3 does not affect the risk of AD
- APOE 4 heightens the risk of AD, associated with down syndrome
