How are some people's brains able to fight off Alzheimer's disease?

 How are some people's brains able to fight off Alzheimer's disease?

Why do some people have the biological signs and damage of Alzheimer's disease, but their memory and intellectual abilities do not decline? Scientists have discovered the answer to this question.

Why do some people have the biological signs and damage of Alzheimer's disease, but their memory and intellectual abilities do not decline? Scientists have discovered the answer to this question.

According to researchers at the Netherlands Institute for Neuroscience, a rare and special type of immature cells in the brains of such people manage to survive and fight off the damage of the disease, so they do not show symptoms of Alzheimer's.

The discovery, published in the journal Cell Stem Cell, raises hopes for the development of completely new treatments to slow the progression of dementia and preserve memory.

Why does Alzheimer's disease affect people differently? This has always been a great mystery in the field of research. According to senior author Evgenia Salta, about 30 percent of older adults with Alzheimer's never develop any symptoms or memory problems. This is called 'cognitive resilience' in medical science.

Scientists believe that understanding what protects the brains of these people can lead to new strategies for preventing and treating dementia.

To investigate this mystery, scientists studied brain tissue donated to the 'Netherlands Brain Bank'. This included brain samples from healthy people, Alzheimer's patients, and people who have survived Alzheimer's despite their brain damage. The research team focused on a small area within the brain's hippocampus, where new neurons can grow.

Using special analytical methods developed for human tissue, scientists found immature cells called ‘immature neurons’ in the brains of people over 80 years old.

The most surprising thing about this research was that the number of these immature cells in the brains of resistant people who did not show signs of Alzheimer’s was not much higher than that of Alzheimer’s patients.

Instead, the biggest difference was found in the function and behavior of these cells. In resistant people, these cells were found to activate special internal systems to fight brain damage and keep themselves alive. In addition, there were significantly fewer signs of inflammation and cell death in such brains.

According to scientist Salta, these cells not only replace the neurons that have been destroyed, but also help keep the brain functional and ‘young’ by supporting the tissues around them. She compared it to ‘fertilizing’ a deforested garden.

However, the researchers clarified that since the research was conducted on dead brain tissue, further studies are needed to prove how these cells communicate in the living brain, and that many other biological factors may also be involved behind this brain resistance.

According to experts, the discovery has changed the traditional thinking about how Alzheimer's damages the brain and has led medical research to a positive direction in how some brains can withstand that damage.