Recently a group of researchers from the Salk Institute injected human brain tissue into laboratory mice. They hoped to see that the human brain tissue would graft with the mouse brain tissue and begin development in a similar way to what occurs in a newborn. Their goal was to study the brain and learn more about healthy brain functions and what causes neurological disorders.  

In the past, scientists have created a cluster of brain tissue called brain organoids which they then study from a petri dish. Organoids, sometimes called “mini brains,” are artificially created from adult human stem cells.  

“Brain organoids are powerful tools for investigating human development and disorders,” Rusky Gage, a researcher at Salk, said.     

However, the Petri dish method only allows the scientists two to three weeks of viable study before the tissue dies. The Salk researchers decided to inject the brain organoids directly into mice in the hopes of it grafting. They were pleased to find that grafting did occur and the tissue lived longer as a result of blood flow, and it integrated into the existing brain functions allowing the organoids to survive for a period of 233 days.  

Many wonder if the mice became smarter than their counterparts without human brain tissue. According to the researchers, no additional intelligence was noted.  The mice still battled the difficulties of the maze just as before. However, this research was not to make a super species of mouse, but rather to better understand brain functions with an eye toward unlocking the mysteries of several brain-related conditions such as autism, Alzheimer’s, dementia, schizophrenia, brain injury and stroke.

They hope that this new method of study will facilitate the testing of promising new drugs leading to quicker cures out in the marketplace and someday to possibly recreate healthy brain tissue which could replace damaged tissue caused by any of these conditions.