Why are scientists producing MINI-brains in mass?
The goal is to try to understand how human intelligence evolved, but it can go one step further.
At some point, during our evolution, the human brain experienced unprecedented growth. Much of this occurred in the neocortex, the external part of our brain, which allowed us to achieve intellectual ability to use language, abstract thinking and other human characteristics.
But how did this jump occur? With the help of dozens of “mini brains ” of chimpanzees grown in the lab, a group of scientists, led by Arnold Kriegstein, are getting closer to answering this unknown.
According to a study published in Cell, Kriegstein team achieved new knowledge about how the human brain evolved by comparing the early development of the human mini-brains, macaques and chimpanzees in a Petri dish, a breakthrough that the study It points out as “cellular anthropology”.
“At birth, the human cortex is twice as big as that of the chimpanzee,” Kriegstein explains in a statement, so we needed to go back much earlier, to embryonic development, to understand the events that drive this incredible growth. ”
These mini-brains aren’t really little brains in a jar. These are groups of different brain cells developed to mimic an animal’s brain and are not able to generate any thought or level of real cognition.
The team closely examined human and chimpanzee brain organoid and observed how specific cell types and gene activity orchestrated their growth. In general, they found several hundred unique and human-specific cell and genetic changes that were associated with the brain.
The study also demonstrated the ability to mass-produce chimpanzee’s cerebral mini-organs, which is itself a revolutionary feat. The team began by gathering pluripotent stem cells (iPSC), skin cells that were reprogrammed into stem cells to become any tissue in the body. Using the IPSC, they were able to develop 56 organoid from the skin of 8 chimpanzees and 10 humans.
“Our ability to take skin cells from an adult chimpanzee, convert them into IPSC and then study their development in the lab is staggering,” concludes Kriegstein. It’s a sci-fi experiment that wouldn’t have been possible 10 years ago.