The ARHGAP11B gene, which is present only in humans and stimulates the development of a new cerebral cortex, could play an important role in the evolutionary separation of humans and monkeys, experts from the Institute of Molecular Cell Biology and Genetics believe. Max Planck in Germany. They told about this in an article in the EMBO Reports magazine.
The new cerebral cortex (neocortex) is a region of the cerebral cortex that is almost undeveloped in lower mammals, while in humans it forms the main part of the cortex and is responsible for higher nervous functions, including conscious thinking and speech. Since research on great apes is prohibited in Europe for ethical reasons, scientists have grown organoids from stem cells – three–dimensional cellular structures several millimeters in size - of the human and chimpanzee brains.
The introduction of the ARHGAP11B gene into the organoid of the chimpanzee brain led to the active formation of stem cells intended for the formation of the neocortex, as well as an increase in the number of neurons in general. Blocking of the ARHGAP11B gene in human brain organoids caused a decrease in the number of stem cells for the formation of the neocortex to the same level as in the organoids of the chimpanzee brain.
In earlier experiments, the same group of scientists showed that ARHGAP11B can enlarge the primate brain. However, it was unclear whether this gene plays a role in the evolutionary increase of the human neocortex.
ARHGAP11B plays a crucial role in the development of the neocortex during human evolution. Given the important role of ARHGAP11B, it can be assumed that some neocortical malformations may be caused by mutations in this gene.