Brain Basics
Plaques
Tangles
Causes/Effects
History
100
How much does the brain weigh?
3 lbs
100
What are plaques?
Abnormal clusters of protein fragments building up.
100
What do tangles destroy?
The vital transport system made of proteins.
100
What leads to the shrinkage of an Alzheimer's patients brain?
Nerve cell death and tissue loss
100
What is the one major distinction between Alzheimer's and senile dementia?
Age
200
How many nerve cells and synapses does an average adult brain contain?
100 billion nerve cells with branches that connect at more than 100 trillion points
200
How are plaques formed?
Plaques are formed by beta-amyloid proteins that are sticky and gradually build up between nerve cells.
200
How is the transport system (affected by tangles) organized in healthy areas? What protein is instrumental in maintaining this organization?
The transport system is organized in orderly parallel strands. Tau keeps these "tracks" straight and stabilizes structures critical to the cell's internal transport system.
200
What are two suspected causes for cell death and tissue loss in Alzheimer's?
Plaques and tangles
200
Describe the Bielschowsky stain.
A silver stain to demonstrate neurofibrillary tangles, nerve fibers and senile plaques in Alzheimer's disease.
300
What is the chief type of cell destroyed by Alzheimer's disease?
Neurons
300
Where do beta-amyloid originate from?
From a larger protein in fatty membrane surrounding nerve cells
300
What happens in areas where tangles form?
The tracks fall apart and disintegrate, causing nutrients and other essential supplies to no longer move through the cells which leads to cell death.
300
In addition to increased severity in the regions of the brain affected in the earliest stages, what other areas get affected in mild to moderate Alzheimer's?
Areas involved in speaking and understanding speech, and your sense of where your body is in relation to objects around you are affected.
300
What is the difference between arteriosclerosis and atherosclerosis?
Arteriosclerosis: thickening and hardening of arteries Atherosclerosis: arteriosclerosis caused by buildup of fatty plaques in the artery
400
Which brain area undergoes especially severe shrinking?
Hippocampus
400
Describe two ways plaques cause brain disruption.
1. Plaque cluster form between neurons preventing cell-to-cell signaling. 2. Activate immune system and trigger inflammation
400
Where do plaques and tangles begin to form in the earliest stages of Alzheimer's? (brain areas involved in what)
They form in brain areas involved in learning and memory, and thinking and planning.
400
What happens (brain and behavior wise) in severe Alzheimer's?
Most of the cortex is severely damaged, the brain shrinks due to cell death, and there is a lost ability to communicate, care for themselves, and recognize others.
400
What is the Hippocratic Theory show for Alzheimer's?
An imbalance in the bodily fluids that lead to "cold" and "dry"
500
What are the three main parts of the brain and one function of each?
Cerebrum - remembering, problem solving, thinking, feeling, movement Cerebellum - coordination, balance Brain stem - automatic functions such as breathing, digestion, heart rate, blood pressure
500
What molecule usually snips the amyloid precursor protein and what happens differently in Alzheimer's disease?
Alpha-secretase usually makes the first snip of the amyloid precursor protein, followed by gamma-secretase. In Alzheimer's, beta-secretase makes the first cut resulting in beta amyloid plaques.
500
The number or neurofibrillary tangles is strongly correlated with what?
The degree of dementia
500
In what other syndromes are plaques and tangles present?
Guam-Parkinson's disease, amyotrophic lateral sclerosis (ALS) motor neuron disease
500
How did Alois Alzheimer become famous?
Using the Bielschowsky stain studying a 51 year old woman's brain who had died from unusual dementia with plaques and tangles at a young age.
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