University of São Paulo: Modern humans produce more brain neurons than Neanderthals, study shows
In a study published in the journal Science , researchers at the Max Planck Institute for Molecular Cell Biology and Genetics in Germany discovered how the brain of modern humans produces more neurons than the brains of Neanderthals. In the study, scientists introduced specific protein variants found in modern humans and similar ones found in Neanderthals into the embryonic neocortex of animals such as mice and ferrets. Brains with the version of the protein found only in modern humans developed more neurons.
“If we compare the brains of Neanderthals with the brains of modern humans, we will see that modern humans have a greater number of neurons on the outside, in a region called the frontal cortex”, explains Merari Ferrari, professor at the Institute of Biosciences (IB) from USP.
According to her, science already knows that the main factors for increasing human cognitive abilities involve the evolution of brain size and its ability to produce neurons, cells that characterize the nervous system and send impulses to the brain. . Another proven fact is that our Neanderthal cousins had a brain of similar size to ours. What still needed to be discovered involved understanding its ability to produce these neurons.
Therefore, one of the conclusions reached by the authors of the study is the hypothesis that the protein transketolase-like 1 (TKTL1) of modern humans, which differs only by a single amino acid from the Neanderthal variant, increases the synthesis of certain lipids necessary to generate the long process of basal radial glial cells that stimulates their proliferation and therefore increases the production of neurons.
The results were obtained by recording the increase in convolutions in the animals’ brains during the experiment. About this, Merari explains that, when observed, it is possible to notice that a human brain has several small circles and their presence indicates a greater number of neurons in the region. “The brains of mice and ferrets are smooth. However, as the scientists expressed the gene [in general, they introduced the protein], there was an increase in the number of neurons and an increase in convolutions”, he explains.
For the professor, who is also part of the Laboratory of Cell Biology of Neurodegeneration at USP, the international discovery may help to understand how the human brain works and how it has developed over the centuries. In addition, it brings important new data to areas such as neuroscience, human evolution, genetics and anthropology. “Research like this is very relevant to human health. [From them] it will be possible to make perspectives on the treatment of neurodegenerative and neurodevelopmental diseases; and better understand pathologies associated with death, replacement and targeting of neurons to their regions.”
The consequences can be numerous, points out the professor, but only from concrete results that scientists from all over the world will be able to take the next step: “Start thinking about their applications”, she concludes.