Question: what happens to the brain during the Alzheimers disease also what causes it and is it genetic?

Dawn Lau answered on 18 Jun 2016:

Such a great question! This is exactly what I’m researching.

When you have Alzheimer’s disease, your brain cells start accumulating proteins called beta-amyloid and tau and they form sticky clumps in your brain. These proteins serve normal functions in your brain when you’re healthy, but in disease conditions they become structurally abnormal and carry out toxicity to the brain. These clumps start in one region of the brain, and because Alzheimer’s is a progressive disorder (meaning it gets worse over time), they spread to different regions of the brain until eventually your brain is full of these clumps. We still don’t know whether these clumps are toxic, but scientists think that the in-between forms of the proteins, might be the most toxic and easily-spread forms.

The toxicity that is spread throughout the brain causes your neurons to stop communicating with each other and when that happens, they eventually die. It is these dying neurons that cause the memory loss and behavioural changes that you see in Alzheimer’s disease. Eventually you lose a lot of neurons and your brain actually shrinks quite a bit. If you compare a normal healthy brain to a diseased Alzheimer’s brain, you can see the difference here: https://www.alz.org/braintour/healthy_vs_alzheimers.asp

There is a genetic component to Alzheimer’s. It can be caused by mutations to certain genes, which can be passed on in families, but that is rare. This is called early onset Alzheimer’s disease, and it tends to show up earlier and is more aggressive form of disease. Only about 0.1% of Alzheimer’s cases are genetic, however. The majority of Alzheimer’s disease is sporadic, which means it is caused by other factors. What these factors are is not clear yet, but this is something many researchers are working on.