A research team in the US has shown that human brain tissue implanted into rats can integrate into its host’s brain, promising to give scientists an entirely new way to study brain disorders – but raising ethical questions too.
Professor Sergiu Pasca and colleagues at Stanford University in California took sesame seed-sized clumps of human brain cells called “organoids” grown in a test tube and implanted them into the brains of baby rats.
In the research, published in the journal Nature, they report that not only does the human brain tissue survive, but it incorporates itself into the rat brain, making connections with rat brain cells and being served by the rat’s blood supply.
The organoids also grew in the rat brain, to about the size of a pea.
The human nerve cells grow about six times larger in the rat than they do in the test tube.
The team then conducted a series of experiments that showed the human brain cells could receive sensory signals from the rat’s…
