Crucial gene for human big brains identified

The crucial gene for human big brains has been identified: thanks to organoids, miniature brain structures grown in the laboratory from stem cells, researchers led by the German Max Planck Institute of Molecular and Genetic Cell Biology and University of Heidelberg , in fact, they found that it is responsible for the greater development of the cerebral cortex than the chimpanzees, our close relatives.

The study, published in the journal Embo Reports, could also lead to treatments for some brain development disorders in the future, since they are likely to be caused by mutations in this gene.

Researchers have developed organoids, just a few millimeters in diameter, from human and chimpanzee brains in the laboratory.

By introducing the gene under study, called ARGHAP11B, into the miniature brains of monkeys, they recorded an increase in brain stem cells and neurons that play a vital role in human beings' extraordinary mental abilities.

Similarly, when the gene was silenced (or the protein it produces was inhibited from functioning) in the human organoid, the same cells decreased, reaching chimpanzee levels.

"The development of these organoids allowed us to investigate a central question," comments Wieland Huttner of the Max Planck Institute, co-author of the study.

"In this way," concludes Michael Heide, of Max Planck and Leibniz Institute for Primate Research, another of the study's authors, "we were able to demonstrate that ARHGAP11B plays a crucial role in the development of the cerebral cortex during human evolution ".