brain start to 'eat itself

Brain start to 'eat itself |  Under what circumstances does the brain start to 'eat itself'?

It is surprising but true that under certain circumstances the brain starts to "eat itself," and this has been proven by science. But there is a special context to this phrase.
What does it mean for the brain to eat itself? This process is actually called "neuronal self-degradation" or "autophagy", meaning the brain starts killing its own cells and this happens when:
1) Lack of sleep
Research has shown that when we don't get enough sleep, some cells in the brain (astrocytes) start destroying healthy cells instead of cleaning up the bad ones. It's as if the brain is killing its own healthy part.
2) Diseases like Alzheimer's
In Alzheimer's, brain cells slowly die and neurons lose their ability to connect with each other, leading to memory and thinking loss.

3) Severe stress and malnutrition
Some cells in the brain (microglia) obtain energy by breaking down their own neurons in the event of stress or lack of energy.

Interesting fact:
Continuous sleep deprivation increases the process of brain autophagy and can be the beginning of diseases like Alzheimer's.