281
A new study by neuroscientists shows, that the cognitive abilities that our ancestors developed over the past millions of years caused the accelerated aging of the human brain.
According to a study by Sam Vickery of Heinrich Heine University and his colleagues, the additional cognitive capabilities that arose after the evolutionary divergence from our closest relatives more than 6 million years ago made the gray matter of the human brain more vulnerable to age-related changes. Although our brain has allowed us to achieve a high level of intelligence and adapt to a variety of conditions, the rate of its degeneration during the aging process is higher than that of other primate species.
In the study, scientists analyzed MRI images of 189 chimpanzees and 480 humans, and compared the brains of other primates, such as baboons and macaques. The scientists hypothesized that it was the enlargement of the human prefrontal cortex, which plays a key role in higher cognitive functions such as memory, language and executive control, that could increase vulnerability to aging. However, the results of the study showed that there was no direct relationship between brain enlargement and the rate of age-related changes in primates.
Average relative cross-species pattern expansion for each OPNMF 17 cluster is shown for (A) human-to-chimpanzee, (B) chimpanzee-to-baboon, and (C) chimpanzee-to-macaque expansion.
The most pronounced changes in the human brain are observed in the prefrontal cortex, which, being the last part of the brain to mature during development, is one of the first to undergo aging. At the same time, in chimpanzees, although there is also a loss of gray matter, these changes are much less pronounced compared to humans. This process, according to the researchers, may be due to a lower density of neurons in this area of the brain, which makes the cells more vulnerable.
The evolutionary enlargement of the human brain, which allowed our species to develop complex cognitive functions, also led to the emergence of a certain "cost" - accelerated degeneration of brain tissue in old age, which makes people more prone to such neurodegenerative diseases as Alzheimer's and Parkinson's.
