by Abigail Mullen
On Monday, April 16, scientists at the Salk Institute published a paper describing the first successful implantation of human cerebral organoids into a mouse. The purpose of the study was to determine if another brain could be grown inside the host organism. In this study, the host brain was able to supply the cerebrums with blood to keep them alive for months. This technique is used to understand human development and test to see if this could be a valid way to grow brain tissue to replace damaged tissue. The paper published in Nature Biotechnology states the mice with human cerebrums are no more intelligent than any other mouse.
The first human brain organoids, small synthetic organs, were created from stem cells in 2013. Scientists think the organoids will be the best model to show how human brains develop, both normally and abnormally, and stem cells can differentiate into any type of cell so they can be made to form brain cells. The scientists at the Salk Institute grew human brain organoids for 31 to 50 days then implanted them into mouse brains. They took out a small piece of the mouse’s brain to make room for the organoid. About 80 percent of the implants were successful. In around two to 12 weeks, the organoids had grown new neurons. At 14 days, most organoids had developed a system of blood vessels. This allowed them to survive for up to 233 days. While the mouse was not able to fully form a new brain, this research is promising work towards being able to culture live brains.
