In his laboratory in Harbin, China, Professor Xiaoping Ren is working on the extreme edge of science: performing head transplants on mice. Video: Max Duncan. Photo: Gilles Sabrié for The Wall Street Journal 
 
 HARBIN, China—Xiaoping Ren stood up after 10 hours hunched over an operating table and looked proudly at his patient, a small black mouse with a new brown head. 
 
 When he took a ventilator off the tiny creature’s throat, the head began breathing spontaneously with its new body. An hour later, the body twitched, and, a few hours after that, the mouse opened its eyes, Dr. Ren recalls. 
 
 Since... 

 Xiaoping Ren has performed over 1,000 head transplants on mice - and wants to move on to monkeys 
 
 Controversial Chinese surgeon Xiaoping Ren has made his name by transplanting mice heads onto different bodies. 
 
 The creatures don't live longer than a few minutes but Dr. Ren has been able to create Frankenstein-like mice with heads that are a different colour from their bodies. 
 
 Now he wants to begin chopping up monkeys in order to get closer to an actual human head transplant. 
 
 According to the WSJ, which shadowed the surgeon during a 10-hour transplant operation, he is “hoping to create the first head-transplanted primate that can live and breathe on its own, at least for a little while.” 
 
 Xiaoping Ren Xiaoping Ren has performed head transplants on over 1000 mice 
 
 Animal rights organisations have blasted the Chinese doctor and his methods. 
 
 "It is deeply disturbing that a researcher has been allowed to subject more than 1,000 mice to these cruel and medically absurd experiments," a spokesperson for Animal Aid told Mirror Online. 
 
 "There is no way in which a surgical procedure that allows a mouse, or even a monkey, to survive for a few minutes is likely to translate into concrete benefits for human patients," they said. 
 
 "Even if the surgery was developed so that mice or primates were kept alive for longer, fundamental differences between species mean there is no guarantee that humans would experience the same results. 
 
 "If individual people want to volunteer to participate in such research, then they are free to make an informed decision, but animals should not be forced to suffer in these pointless and macabre experiments." 
 
 Experts meanwhile have likewise branded the work ridiculous - citing that human head transplants are controversial and a long way from being medically possible. 
 
 They could offer a new life for paralysed or quadriplegic patients, but the ethics of the procedure are incredibly complex. 
 
 Arthur Caplan, director of medical ethics at New York University’s Langone Medical Centre said the bodies of head transplant patients “would end up being overwhelmed with different pathways and chemistry than they are used to and they’d go crazy.” 
 
 He added: “It’s not like you can unscrew your head and put it on someone else.” 
 
 Dr Hunt Batjer, president elect of the American Association for Neurological Surgeons, added: “I would not wish this on anyone. 
 
 “I would not allow anyone to do it to me as there are a lot of things worse than death.”
– A head transplant may sound like something out of a horror movie, but Dr. Xiaoping Ren has completed about 1,000 on mice. This summer, he'll attempt his first such procedure on a monkey in a case that will be closely watched. Ren, who worked in the US for more than 15 years, may conduct the experiment in his native China, where he has worked since 2012 with the government's strong support and $1.6 million in grants, as Beijing seeks to become what the Wall Street Journal calls a "scientific powerhouse." Such a test may not even be possible in America, where other controversial Chinese research has met with harsh criticism. An animal rights group tells the Daily Mirror Ren's mice experiments alone are "cruel and medically absurd." In China, those concerns take a backseat to hopes that human head transplants can one day help those with spinal-cord injuries, cancer, and other diseases. But first, "we have to make an animal model with long-term survival," says Ren, 53. Mice with transplanted heads have survived for at most a day. Ren, who will collaborate with another surgeon interested in human head transplants, first makes a clean cut to detach the donor head from its body, while the head of the body to be donated is separated at midbrain so the heart can remain beating. Blood vessels from the donor body are then attached to the recipient head using silicone tubes before the head's spinal nerves are connected. The bone from the connecting vertebrae is rebuilt with pins, screws, and plates, then the blood vessels, muscle, and skin are joined with microscopic sutures. When Ren turns his procedure to monkeys—long-tailed macaques, specially—he will aim to connect just 10% to 20% of 100 billion spinal-nerve fibers—enough to allow the monkey to breathe and move muscles voluntarily. Should Ren eventually reach the "next frontier" with human transplants, a much higher percentage of connections will be needed. (Think the idea is crazy? You're not alone.)