Miniature human-brain-like structures transplanted into rats can send signals and respond to environmental cues picked up by the rats’ whiskers, according to a study. This demonstration that neurons grown from human stem cells can interface with nerve cells in live rodents could lead to a way to test therapies for human brain disorders. Scientists would like to use brain organoids — tiny brain-like structures grown from human stem cells — to study neurodegenerative and neuropsychiatric disorders that humans develop. But the organoids mimic human brains only so far.

https://www.nature.com/articles/d41586-022-03238-x#:~:text=The%20team%20trained%20the%20rats,help%20drive%20the%20animals'%20behaviour.