This Surgeon Just Transplanted a Second Head to a Rat -- Are Humans Next?

The world's first head transplant just happened. Sergio Canavero, an Italian neurosurgeon who made news in 2013 with his bold proposal of conducting the world's first head transplant, revealed that he has given a rat a second head.

Back in 2013 when Canavero announced his intent to conduct a full head transplant using the so-called GEMINI spinal cord fusion protocol, the news got a hysterical reaction from the public. However, the study, reported in Surgical Neurology International (SNI), aims to once and for all clear the hysteria through "a series of proof-of-principle papers."

Canavero, together with another surgeon, Xiaoping Ren, used a method of cutting and reconnecting spinal cords. However, it's not as simple as it seems. The researchers said that in order for a spinal cord fusion to be successful, the cut should be sharp enough to minimize cord damage in the white and gray matter levels of the spinal cord.

The gray matter and white matter are important to be regrown so that the host body could regain sensorimotor skills. The study notes that the gray matter core is vital to make the host body move and feel -- a different view compared to past assumptions that the white matter is solely responsible for these functions.

With regard to the sharp cut on the spinal cord, the researchers noted that even though a sharp cut may affect a degree of mechanical disruption, it poses "no obstacle to regrowing neuritic extensions from the spinal propriospinal neurons." Recovery for the head transplant is expected to only last for a few days or weeks.

According to IFL Science, the two-headed rat in Canavero's study only lived for 36 hours. He has also tried a head transplant on a dog, but the details for that study has not been released yet.

In light of the recent study, the big question now is -- will head transplants on humans be possible?

The study said that performing such experiments on humans will bypass ethical concerns and the only way to test this new procedure is in brain-dead organ donors.

"Despite these exciting animal experiments, the proof of the pudding rests in human studies. The only ethical – and expeditious – way is to test GEMINI in brain dead organ donors before explantation during a 6-hour window during which the cord is severed, PEG applied, and motor conduction assessed distally," the researchers wrote.