NEWS - Researchers compared the brains of humans (Homo sapiens), chimpanzees (Pan troglodytes), olive baboons (Papio anubis) and rhesus monkeys (Macaca mulatta) to gain an evolutionary perspective on the aging process. The large prefrontal cortex in humans provides an evolutionary and cognitive advantage over nonhuman primates, but it comes at a cost.
The human brain has been accumulating networks that aid in decision-making and self-control since it diverged from a common ancestor with chimpanzees more than six million years ago. But the same brain region is also the most at risk of deterioration with age.
The frontal lobes in the human brain, which mature the slowest, show the fastest signs of aging. The findings support a theory known as ‘last in, first out’. Some of the later-maturing regions that are most vulnerable to aging have also evolved the most recently.
The researchers analysed noninvasive magnetic resonance imaging (MRI) scans from 189 chimpanzees aged 9-50 years and 480 humans aged 20-74 years. The brains of both species are broadly symmetrical across the hemispheres and share many similar clusters of anatomical structures, particularly in the prefrontal cortex.
The prefrontal cortex is involved in complex cognitive functions, such as language, working memory, time perception and decision-making. Damage to this region is linked to Alzheimer’s and dementia. The researchers then measured the amount of grey matter that decreased over time as a sign of aging in chimpanzees up to age 50 and in humans up to age 58.
Humans experienced the greatest decline in the frontal cortex, while chimps experienced the greatest decline in a central structure involved in habit formation and rewarding behavior called the striatum. Brain regions involved in visual processing and motor skills were less susceptible to aging in both species.
The fastest evolutionary growth occurred in the prefrontal cortex, one of the areas most susceptible to aging. A structure hidden deep in the brain involved in processing emotions and body signals called the insula also showed rapid evolutionary growth and a high risk of aging.
The researchers also compared chimpanzees with olive baboons and rhesus monkeys. They found no such association between brain areas undergoing rapid evolutionary expansion and rapid aging suggesting that this feature may be unique to human brain evolution.
Original research
Sam Vickery et al. The uniqueness of human vulnerability to brain aging in great ape evolution. Science Advances, 10,eado2733 (2024), DOI:10.1126/sciadv.ado2733
The human brain has been accumulating networks that aid in decision-making and self-control since it diverged from a common ancestor with chimpanzees more than six million years ago. But the same brain region is also the most at risk of deterioration with age.
The frontal lobes in the human brain, which mature the slowest, show the fastest signs of aging. The findings support a theory known as ‘last in, first out’. Some of the later-maturing regions that are most vulnerable to aging have also evolved the most recently.
The researchers analysed noninvasive magnetic resonance imaging (MRI) scans from 189 chimpanzees aged 9-50 years and 480 humans aged 20-74 years. The brains of both species are broadly symmetrical across the hemispheres and share many similar clusters of anatomical structures, particularly in the prefrontal cortex.
The prefrontal cortex is involved in complex cognitive functions, such as language, working memory, time perception and decision-making. Damage to this region is linked to Alzheimer’s and dementia. The researchers then measured the amount of grey matter that decreased over time as a sign of aging in chimpanzees up to age 50 and in humans up to age 58.
Humans experienced the greatest decline in the frontal cortex, while chimps experienced the greatest decline in a central structure involved in habit formation and rewarding behavior called the striatum. Brain regions involved in visual processing and motor skills were less susceptible to aging in both species.
The fastest evolutionary growth occurred in the prefrontal cortex, one of the areas most susceptible to aging. A structure hidden deep in the brain involved in processing emotions and body signals called the insula also showed rapid evolutionary growth and a high risk of aging.
The researchers also compared chimpanzees with olive baboons and rhesus monkeys. They found no such association between brain areas undergoing rapid evolutionary expansion and rapid aging suggesting that this feature may be unique to human brain evolution.
Original research
Sam Vickery et al. The uniqueness of human vulnerability to brain aging in great ape evolution. Science Advances, 10,eado2733 (2024), DOI:10.1126/sciadv.ado2733