Warning: This article contains graphic content.
We have been promised a head transplant by next year, and the main brain behind the highly controversial procedure shows no signs of retracting his wild claim. Quite the opposite, in fact, as the pioneering surgeon has now announced the procedure has been successfully carried out on a monkey.
As revealed by Motherboard and New Scientist, Italian doctor Sergio Canavero has teased the press with some details on progress made so far by himself and collaborator Dr Xiaoping Ren of China’s Harbin Medical University, among others. Ren has invested a significant amount of time perfecting the technique in mice, having performed the transplant on more than 1,000 mice. The animals were able to breathe and drink after the 10-hour surgery, but only lived for a matter of minutes.
Now, according to Canavero, Ren’s team has carried out the transplant on a monkey. Although, even if this does turn out to be true, it doesn’t seem that any significant increments have been made since the ‘70s, when Dr Robert White managed the same feat. While the animals both reportedly survived the surgeries, neither involved an attempt to fuse the donor and recipient spinal cords. Though Ren did take a leaf out of White’s book, cooling down the brain to -15oC (5oF) in order to protect the nervous tissue from damage. After cleanly severing the spinal cords, blood vessels of the transplanted head were joined to those of the donor body.
“The monkey fully survived the procedure without any neurological injury of whatever kind,” Canavero claims. But considering the fact that the animal was euthanized after just 20 hours for ethical reasons, alongside the fact that the spinal cords were not connected, this assertion seems premature, to say the least. Regardless, according to Ren, the idea behind the experiment was not to investigate potential length of survival, but to work out how to keep the brain supplied with blood to prevent the tissue from starving of oxygen and nutrients.
A graphic picture of the subject, a screenshot of a YouTube video, can be seen below.
What is perhaps most dubious about this announcement is the fact that Canavero chose to go to the press before the work is published, an approach that is considered taboo among the scientific community. Canavero says that seven papers are due to appear in the journals Surgery and CNS Neuroscience & Therapeutics. Both Motherboard and New Scientist reached out to the editor of the former, Michael Sarr, who confirmed that the journal had reviewed two papers so far, but that further rounds of editing are required prior to publication.
While Sarr was quick to point out concerns over the sensationalism and ethics of the procedure, he noted that the journal has significant interest due to the implications of the research. In particular, one paper is concerned with nerve regrowth following spinal cord injury, which has the potential to offer hope to a tremendous number of people suffering such debilitating trauma.
But Canavero and Ren are certainly not the only scientists working towards this laudable goal. A group led by C-Yoon Kim at South Korea’s Konkuk University, for instance, has been severing the spinal cords of live mice and then re-fusing them with the aid of a substance called polyethylene glycol, which helps the fatty membranes of cells meld together. Shown in a video, the animals were later able to hobble around again. Other teams are also trialing different methods, such as stem cells or electrical stimulation.
Whether Canavero will be in a position to perform the transplant on a human subject next year remains doubtful, so for now, it’s best to wait with skepticism until the papers are published.