How fast does your brain age? Scientists identified key genes

Your brain can start aging much faster when you turn 65. And maybe not start. It turns out that this depends on which version of a particular gene is contained in your genome. This was discovered by scientists in the framework of a recent study. In the course of the study, scientists discovered a gene that controls the rate at which your brain ages, yet they argue that a particular version of this gene can offer protection against a large number of age-related neurological diseases, such as senile dementia.

A gene that can protect you from dementia?

This gene, called TMEM106B, begins to act roughly when a person is 65 years old. Shortly thereafter, people who have a bad version of this gene, the brain will look 10-12 years older than the brains of those people who have a good, effective version of this gene. This discovery can help doctors determine which people are at increased risk of developing neurological diseases because they have a bad version of the gene. It can also help in creating medicines whose effects will be targeted at this gene in order to provide people with a healthier aging brain.

The most important of all genes

In recent years, scientists have discovered a large number of genes associated with Alzheimer's and Parkinson's, as well as with other neurological diseases. However, these genes are able to explain only a small part of these diseases. As is known to date, the main risk factor for the onset of neurodegenerative diseases is aging. Something changes in the brain when you grow old, and this leads to the fact that you become more prone to brain diseases. The genetic commands that the TMEM106B gene gives away can be this "something". And these teams can either protect themselves from the problems caused by aging, or exacerbate them. If you look at a group of older people, some of them will look older than others, and some will be younger. Precisely the same difference in aging can be observed in the frontal cortex, the brain region responsible for complex thought processes.

A new study against the background of previous

Previous studies linked this gene with a rare form of dementia, called frontal-temporal degeneration. However, a new study demonstrates that this gene is much more closely related to aging of the brain and determines how well the elderly retain their cognitive functions. To determine what could control the aging of the brain, two researchers analyzed the genetic information obtained from more than 1200 human brain samples belonging to those people who had not been diagnosed with any neurodegenerative diseases when they were still alive. They concentrated on several hundred genes, the efficacy of which had previously either increased or decreased in the course of human aging. From these data, the scientists compiled a diagram, which they called "differential aging". This chart showed the difference between the present (or chronological) age of the brain and its actual age.

What is the peculiarity of this gene?

One gene, the same TMEM106B, stood out against the others, showing itself as the engine of differential aging. It turns out that this gene controls inflammation and loss of neurons in the brain. But this gene has two forms, more precisely, two alleles: the first of them is associated with an increased risk of accelerated aging of the brain, while the other is protective and prevents the acceleration of aging. Each person has two versions of this gene in the genome, and in about thirty percent of the population, both versions are bad. In fifty percent of the population, one allele is protective, and the other has a negative effect on the brain, but the remaining twenty percent have two protective alleles.

Variety of combinations, and what does this lead to?

As far as can be judged at the moment, the effect of two negative alleles is cumulative. This means that the brain of a person who has two negative alleles looks five years older than the brains of people who have only one negative allele. And their brain, in turn, looks five years older than the brain of those people who do not have any negative alleles at all. So one of the main hypotheses about this gene is that, according to which TMEM106B controls the systematic reaction in the human brain to age-related stressors. In the same study, scientists looked at the brain of those people who during life suffered from Alzheimer's or Huntington's disease and found exactly the same effect of this gene on the aging of their brain. It is worth remembering that this gene begins to function when reaching the age of 65 years, before that all people are at the same level.