Alzheimer's Disease: A Silent Killer

The human brain possesses amazing capabilities that make it the most amazing and powerful organ in the body. That is, when it's functioning properly. When it's not the effects can be devastating. Take a look at the diagram below (1):

The brain on the left side is normal, and the brain on the right has severe Alzheimer's (a neurodegenerative disease). Notice how the brain shrinks. The small seahorse-shaped hippocampus in the medial temporal lobe is crippled, thus losing the ability to store memories. But... how does this all happen?

It all starts in the wrinkled cerebral cortex, where action potentials travel across the synapses of the billions of neurons in the brain. Chemical neurotransmitters jump across these synapses and carry the signals to other neurons (pictured below)(2). The brain is functioning properly. However, in patients with Alzheimer's disease, proteins known as Beta-Amyloid begin to clump together and important Tau proteins begin to fall apart.

The result? Amyloid plaques and neurofibrillary tangles that block neurotransmission in the synapse. The neurons deteriorate and the patient lose the ability to think and store memories. A person with Alzheimer’s gradually loses their ability to function properly. The disease is ultimately fatal.
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Image Credit:
(1) Alzheimer's Brain vs. Normal Brain. sundownerssyndrome.org/wp-content/uploads/2019/03/Brain-shrinkage-dementia-alzheimers-clean.jpg.

(2) Science Neuron Synapse Biology. cdn.pixabay.com/photo/2014/04/02/11/17/science-305773_960_720.png.

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