Memory, alzheimer's

Question 1

What is the defination of dementia?

Answer 1

A chronic or persisting disorder of the mental process caused by disease or injury marked by memory loss, personality changes and impaired reasoning. Has to impact daily activity and not be a delirium.

Question 2

What are the changes found in the brain of alzheimer’s patients brains microscopically and microscopically?

Answer 2

Macro:
Atrophy - widened sulci and reduced gyri
Enlarged ventricles
Reduced amygdala and hippocampus

Micro
Neurofibrillay tangles and amyloid plaques
A reduction of cholinergic neuron fibres projecting into the cortex.

Question 3

How are neurofibrillary plaques created?

Answer 3

They are compsed of paired helical filaments of tau protein. Tau stabilises the cells microtubules. In alzhiemers tau becomes excessively phosphorylated and thus cant bind. It accumulates and aggregates into paired helical filaments and then larger tangles.

Question 4

What causes the symptoms of Alzhiemer’s disease?

Answer 4

A reduction in cholinergic neuron fibres projecting into the cortex. It impairs behaviour and cognition.

Question 5

How are beta amyloid plaques created?

Answer 5

Amyloid precursor protein is usually cut by alpha and gamma secretases. This creates a protein that is soluble and is removed. If it is cleaved by Beta and gamma then the fragment is not soluble and creates an beta amylod monomer. Clumps of these are beta amyloid plaques. They can disrupt neuron transmission, start an immune response that damages neurons