Scientists talked about the possible protection of the brain from Alzheimer's disease

Some people have changes in the brain that are characteristic of Alzheimer's disease, but their memory and ability to think remain intact for a long time. This phenomenon is called cognitive resilience. Researchers have discovered a possible connection between this phenomenon and the activity of immature nerve cells that persist even in old age. The role these cells can play in protecting the brain from the effects of Alzheimer's disease is described in the Izvestia article.

What cells have been found in the brains of people over 80 years old?

Researchers from the Netherlands Institute of Neuroscience studied brain tissue samples from people from three groups: without identified pathological changes, with dementia in Alzheimer's disease and with changes characteristic of the disease, but without pronounced cognitive impairment. The work was published in the journal Cell Stem Cell.

The researchers focused on a small area of the hippocampus, a brain structure involved in memory formation. They were interested in immature neurons, that is, nerve cells that have not yet acquired all the characteristics of mature neurons. Such cells were found in all three groups, including those with an average age over 80 years.

Scientists have studied the behavior of the brain in Alzheimer's disease

Why was the behavior of the cells more important than their number?

Initially, researchers assumed that people who maintain clarity of thought in the presence of pathological changes associated with Alzheimer's disease would have more immature neurons. Scientists have considered the possibility that these cells help compensate for the loss of damaged nerve cells. However, the differences in the number of immature neurons between the groups turned out to be significantly less than expected. This led the researchers to pay attention not so much to the number of cells as to their activity.

Initially, researchers assumed that people who maintain clarity of thought in the presence of pathological changes associated with Alzheimer's disease would have significantly more immature neurons. However, the difference in the number of these cells between the groups turned out to be much smaller than expected.

This suggested that cognitive resilience may be related not so much to the number of immature neurons, but rather to the characteristics of their activity and response to brain damage. Thus, the differences could lie in how the cells respond to adverse conditions, rather than in how many of them are in the brain.

Scientists have reported on a new way to protect the brain in Alzheimer's disease

How immature neurons can protect the brain

The researchers suggest that immature neurons can serve not only as a potential source of new nerve cells, but also participate in the maintenance of the surrounding tissue. According to the authors' hypothesis, they can help the brain maintain functionality even with the accumulation of changes associated with Alzheimer's disease.

However, the study does not prove that these cells actually perform such a protective function: the conclusion is based on the discovered biological patterns, and not on direct experimental confirmation.

In his work, the researcher compares the possible role of these cells with fertilizer in a garden that has begun to deteriorate. In other words, they can help maintain the conditions necessary for other nerve cells to function, even as disease-related changes accumulate in the brain.

At the same time, scientists are still considering such a function as a possible explanation for the results, and not as an established mechanism of protection against dementia.

Scientists have reported on the mechanism of brain protection against Alzheimer's disease

Why don't scientists consider this connection proven yet?

The study revealed differences in the activity of immature neurons, but did not establish exactly what function they perform in the human brain. The scientists analyzed tissue samples and the biological signs found in them, but did not conduct experiments that would directly confirm the protective effect of these cells.

In addition, the presence of immature neurons does not in itself prove that new nerve cells are constantly being formed in the aging human brain. It also does not mean that it is these cells that prevent the development of dementia.

In the future, the researchers plan to study how immature neurons interact with neighboring brain cells. This will help to find out whether they are involved in maintaining cognitive functions and what processes may underlie their possible protective role.