Alzheimer's disease Flashcards
What is the most common type of dementia?
Alzheimer’s disease
What are some of the histopathological features of Alzheimers?
Amyloid plaques: Neuritic plaques and diffuse plaques
Neurofibrillary tangles
What are neuritic plaques?
large bulbous structures that are dystrophic and degenerating.
What are diffuse plaques?
plaques that contain b-amyloid protein fibres
Who was the first to discover neurofibrillary tangles?
Alois Alzheimer
In the pre-clinical stages of Alzheimers, what causes the amyloid plaques?
The release of AB peptides from the amyloid precursor protein which then damages neuronal processes and synapses
Mutations at or near to chromosome 21 have been discovered in familial AD
Amyloid hypothesis- chromosome 21 contains the APP gene. People with Down’s syndrome invariably develop AD and they have an extra copy of chromosome 21.
The Amyloid hypothesis of Alzheimer’s states that AD is characterised by….
amyloid plaques which contain mainly aggregated AB derived from amyloid precursor protein (APP)
What are the 3 major risk factors of AD?
Age, family history and sex (higher prevalence in females after 75yrs)
What is the main risk factor for Familial AD?
genetic mutations
What is the only know risk factor of Sporadic AD?
Apolipoprotein
Familial AD is a rare form of AD, only affecting less than __% of AD patients.
10
All FAD is early-onset and it caused by mutations on which chromosomes?
1, 14 and 21 (APP)
Apolipoprotein is the only known risk for Sporadic AD. It increases your susceptibility but there is no causal relationship. What is APOE?
A substance that carries cholesterol in the bloodstream
E2, E3 and E4 are alleles of the apolipoprotein. Which one is the most common in the general population?
E3
Name a neurotransmitter that is important for memory?
acetylcholine
What are the two types of acetylcholine receptors?
muscarinic and nicotinic
The Cholinergic hypothesis of geriatric memory dysfunction states that significant functional disturbances of the _____ occur in aged and demented people.
cholinergic systems
Cholinergic hypothesis: there is a correlation between severity of dementia and _____________ activity and cell loss in cholinergic cells.
cholineacetyltransferase activity (chAT)
What is one piece of evidence supporting the Cholinergic hypothesis?
Cholinergic antagonists induce amnesia in people and animals
What is the current treatment of AD?
Donepezil (Aricept)- acetylcholinesterase inhibitor
What test do physicians use to diagnose AD?
Mini-mental state examination
Moran et al (1995) found that transgenic mice expressing human form of APP with a mutation had _____-________ disrupted ________ _______ in water maze
age-dependent, spatial memory.
