The name of Sergio Canavero has been circulating in the world of neurosurgery for some years, mainly due to his intention to transplant a human head onto another body. The technical details about the process were published on NeoTeo in mid-2013, but now, the same surgeon has reported successes in experiments with mice, rats, and a dog, using the chemical PEG to repair their spinal cords. As expected, other experts rejected the presented results, demand more evidence, and insist that the procedure "not ready" for humans.
The promise and the publications
When we talk about repairing the spinal cord and enabling a person to recover movement capacity (whether partial or total), the message comes through clearly. However, once the possibility of transplanting heads enters the equation, the first idea that forms is that of a somewhat mad scientist. Believe it or not, humanity began exploring that complex territory at the beginning of the 20th century, with special emphasis between the 1950s and 1970s. In recent times, head transplant has been associated with Italian neurosurgeon Sergio Canavero, who announced that the procedure and technology will be ready by the year 2017, and even already has a Russian volunteer suffering from spinal muscular atrophy. Recently, Canavero published a series of studies in the Surgical Neurology International, where he describes experiments with animals using polyethylene glycol or PEG to reconnect damaged spinal cords.
Animal experiments with PEG
The information includes short videos (Warning: They may be sensitive for the reader) in which one observes a mouse, a rat, and a dog in different phases of recovery. Canavero says that the technique used to restore mobility in the dog, whose spinal cord was cut by 90 percent, will be the same one that will make head transplant possible in 2017. The evaluation of PEG began with C-Yoon Kim from Konkuk University and his team, who, working closely with Canavero, cut the spinal cords of 16 mice. Eight of them received PEG (the other eight served as a control group), of which five survived and recovered a certain amount of movement capacity. At this point, a team from Rice University joined in, working on an "optimizer" for PEG, a kind of graphene scaffold that assists in neuronal development and signal transmission. The combination of both techniques was applied to ten rats, but this is where doubts begin: four of the five rats that received the optimized PEG died due to a flood in the laboratory, while the fifth managed to move around and eat after two weeks.
Doubts and criticism
This brings us to the case of the dog, which supposedly had a 90 percent interruption in its spinal cord. Within three weeks, the dog was already able to walk, and the team claims it can move its tail and pick up objects. Still, in the published studies there is no solid evidence that such an interruption was actually performed. On one hand, the absence of histological data on the dog's spinal cord and the lack of a control are criticized, and on the other, announcing that four animals died in a flood does not qualify as a report. The main point, which is head transplant, seems to be much further away than Canavero believes. According to bioethics professor Arthur Caplan from New York University, this kind of work places Canavero and his team 'three to four years' away from a spinal cord repair, and 'seven to eight years' away from a transplant.
