The neuropathology of dementia Flashcards
The anterior part of the brain (frontal lobe) tends to be involved in which 3 functions?
Executive functions
1) Motor
2) Planning
3) Strategic thinking
The more posterior part of the brain (parieto-occipital lobe) is involved in which 2 main functions?
1) Perception and integration of sensory stimuli
2) Encoding knowledge
Which part of the brain is involved in ‘executive functions’?
Frontal lobe
What 5 functions is the limbic system involved in?
1) Arousal
2) Emotion
3) Motivation
4) Attention
5) Memory
The thalamus is an important structure in what system?
The sensory system
The basal ganglia is an important structure in what system?
The motor system
What is cognition?
The sum of brain functions which allows us to integrate in the environment
Give the 5 main intellectual skills?
1) Learning and memory
2) Language
3) Visuospatial skills
4) Emotion
5) Personality
Which 2 parts of the brain are affected in corticobasal degeneration?
Cortex and Basal ganglia
Temporal, frontal and parietal degeneration occurs in which disease?
Alzheimer’s disease
Multifocal degeneration occurs in which condition?
Corticobasal degeneration
Mutations in which 4 genes are known to be associated with Alzheimer’s disease?
1) Amyloid precursor protein amplification on Chr 21 - can be due to trisomy at birth or an aquired mutation
2) Presenilin 1 on Chr 14 (involved in amyloid processing)
3) Presenilin 2 on Chr 1 (involved in amyloid processing)
4) Apo E on Chr 19 - to dowith stability of beta amyloid deposits
Which 2 proteins are the main ones involved in Alzheimer’s disease?
1) B-amyloid
2) Tau
Which is the main protein involved in dementia with Lewy bodies and Parkinsons?
alpha-synclein
Which 4 proteins are commonly involved in dementia?
1) B-amyloid
2) Tau
3) alpha-synclein
4) Ubiquitin
What are amyloid proteins?
Insoluble fibrous protein aggregates
Where do amyloid proteins arise from and how do they form aggregates?
Arise from inappropriately folded versions of proteins and polypeptides present naturally in the body - these misfolded proteins alter their proper configurations so that they interact with one another forming insoluble fibrils
What is the role of amyloid proteins in disease?
Have been associated with 20 serious human diseases in that abnormal accumulation of amyloid fibrils in organs may lead to amyloidosis and may play a role in various neurodegenerative disorders (B-amyloid)
What are tau proteins?
A group of proteins that stabilize microtubules in neurons
How may isoforms of tau proteins exist?
6
What happens when tau proteins are defective - how are tau proteins affected in Alzheimer’s disease?
When tau proteins are defective the microtubules become instable and dysfunctioning - In AD Tau gets hyperphosphorylated and microtubules become tangles
How do amyloid plaques and tangles differ in where they form?
Amyloid plaques = extracellular
Tangles = intracellular
What is the link between amyloid plaques and tau?
Amyloid plaques can induce the cell to produce tangles ie. interrupting the function of tau