Is a brain transplant possible?

We posed this question to the brain panel. Katie - So in fact, the idea of transplanting brains did have some media attention earlier this year. An Italian neuroscientist wrote an article which had quite a lot of discussion suggesting that a brain transplant could theoretically be achieved by transplanting the whole human head onto a donor body. He proposed a method for reconnecting the severed spinal cords.

In this paper, he referred to the work in 1970s of Dr. White and he transplanted a rhesus monkey head onto the body of another rhesus monkey. The monkey was apparently able to see and smile and taste, and in Dr. White's words, 'bite' and he did this with the idea that eventually, human head could be transplanted onto a donor body. It might help people who had healthy brains but some degenerative illness of the body. So, while the animal awoke, it was reported to live for a very short time. It didn't really have any use of the body because they weren't able to reconnect the spinal cords.

Hannah - And has that study been replicated since the 1970s?

Katie - Well, no. It hasn't been replicated. Of course, the ethics of doing a research programme like that now would be very questionable. It just wouldn't be allowed.

Bill - The easiest part would probably be connecting up the blood supplies, but connecting up the broken nerves is a real problem especially in this central nervous system, the spinal cord. However, you can transplant brains in embryos. You can transplant an embryonic frog brain from one frog to another. You can transplant embryonic chick brain to a quail. Lots of brain transplants are possible. It's when you get to the mammals that it becomes particularly challenging because the nerves don't regenerate so well and they don't cross cuts. So, when you cut a nerve cell axon and you want that cut nerve then to be able to regenerate its axon and make connections with the appropriate targets, it has a really hard time doing that in a mammal.