A surgeon who wants to perform the world's first human head transplant has been practising on rats.
Sergio Canavero and colleague Xiaoping Ren sewed the head of one rat onto another and had both heads survive for about 36 hours, they claim in a paper published in CNS Neuroscience & Therapeutics.
A third rat was attached to the Frankenstein creature, supplying blood flow to keep both the donor and recipient alive during the procedure.
It follows previous experiments by Dr Canavero, including the severing and reattachment of a dog's spinal cord and a monkey head transplant. The monkey head transplant apparently worked "without any neurological injury of whatever kind", but the creature was euthanised after 20 hours for ethical reasons.
The team plan to carry out a human head transplant later this year at Harbin Medical University in China. The donor was originally going to be wheelchair-bound Russian man Valery Spriridonov, who has Werdnig-Hoffmann disease, but the pair now say it'll be an unnamed Chinese citizen.
A "high number of volunteers from all over the world came forward", Dr Canavero said in a statement.
"The final decision is only made immediately prior to the operation, as it also depends on the body donor, who has to be compatible with the receiver in many ways."
If the operation is successful, Dr Canavero says within a few years people whose heads have been cryogenically frozen could be woken up and reattached to new bodies.
Dr Canavero has reportedly asked Facebook billionaire Mark Zuckerberg to fund the research.