Thursday, February 4, 2016

Head transplant 3

A surgeon claims to have carried out the first head transplant on a monkey ahead of plans to attempt the controversial procedure on a human by the end of next year.

Italian Professor Sergio Canavero, Director of the Turin Advanced Neuromodulation Group and researchers at Harbin Medical University in China posted pictures of the creature whose head appears to have been grafted onto the body of another animal.
Stitches can clearly be seen surrounding the neck, which looked to be entirely severed.
According to Prof Canavero, the team led by Xiaoping Ren, connected the blood supply to prove that the animal could survive without suffering brain injury. They have not yet attempted to join the spinal cords so if the animal survived it would be completely paralysed.
“The monkey fully survived the procedure without any neurological injury of whatever kind,” says Prof Canavero, but said it was only kept alive for only 20 hours after the procedure for ethical reasons.

Ren has also tested some experiments on human corpses.

“We’ve done a pilot study testing some ideas about how to prevent injury,” he said.
The experiments are reported in a set of seven papers which are due to be published in the journals Surgery and CNS Neuroscience and Therapeutics.

The papers also claim to have shown that spine fusion technology developed by Canavero ‘has a strong rationale’ and works in mice allowing them to recover motor function. The team claims that crucial nerve fibers regrew.

A press release ahead of the publication said: “A full monkey head transplant has been successfully accomplished by Prof Ren’s group in China with the goal of testing cross-circulation and hypothermia as an effective neuroprotective strategy.

“The first studies on human cadavers have already begun in China and will be expanded shortly.
"The plan for the first human head transplant is on schedule, towards its expected date of realization, Christmas 2017. “

Canavero shocked the world last year when he said that he would be ready to transplant a human head within two years. He wants the first patient to be 31-year-old Russian, Valery Spriridonov, who has a genetic muscle-wasting disease.

Spriridonov, the Russian patient, will only be able to receive a new body in Russia, which will require a commitment from Russian authorities.

It is claimed that initial talks with Russian surgeons have already taken place and the team are hoping to approach Facebook founder Mark Zuckerberg for finance.

In the meantime, Vietnam has offered itself to host future head transplants.

“I would say we have plenty of data to go on,” said Prof Canavero. “It’s important that people stop thinking this is impossible. This is absolutely possible and we’re working towards it.”

However the fact that the team has press released their work before it has been published an peer reviewed has left some scientists anxious about the validity of their claims.

“It’s science through public relations,” Arthur Caplan, a bioethicist at New York University School of Medicine told New Scientist.

“When it gets published in a peer-reviewed journal I’ll be interested. I think the rest of it is BS.”

Thomas Cochrane, a neurologist at Harvard Medical School’s Centre for Bioethics, also told the magazine Canavero’s press release was unorthodox. “It’s frowned upon for good reason,” he said.
“It generates excitement before excitement is warranted. It distracts people from actual work that everyone can agree has a valid foundation. As far as I can tell, that operation has mostly been about publicity rather than the production of good science.”

“If the so-called head transplant works, this is going to open up a whole new science of spinal cord trauma reconstruction,” says Michael Sarr, editor of the journal Surgery and a surgeon at the Mayo Clinic in Rochester, Minnesota. “

We are most interested in spinal cord reconstruction using head transplantation as a proof of principle. Our journal does not necessarily support head transplantation because of multiple ethical issues and multiple considerations of informed consent and the possibility of negative consequences of a head transplant.”


  1. In a 1978 essay, titled Where Am I?, the philosopher Daniel Dennett suggested that the brain was the only organ of which it’s better to be a transplant donor than recipient. Now Italian neurosurgeon Sergio Canavero wants to turn philosophical thought experiments into reality by transplanting the head of Valery Spiridonov, who suffers from a debilitating muscle wasting disease, onto the healthy body of a dead donor.

    Beside posing questions about personal identity, there are more prosaic challenges that must first be overcome. The brain would have to be kept alive during surgery by cooling it to 10-15°C, and the immune system would need to be powerfully suppressed to prevent transplant rejection. But the greatest hurdle may be how to restore connections to the spinal cord. Without this connection the brain would have no control of its new body.

    In 1970, Robert White at Case Western Reserve University performed a head transplant using monkeys. Without spinal connections the animal was paralysed from the neck down for the brief time it could be kept alive.

    Canavero believes the time is right to revisit this controversial procedure, due to recent advances in surgical techniques and scientific understanding. He hopes that his “GEMINI” protocol – combining polyethylene glycol to fuse nerves with electrical stimulation of spinal circuits – will allow his patient to move and even walk following the procedure.

    Breakthrough or spin?

    Canavero has been criticised for publicising his ideas in the media before releasing peer-reviewed research papers. Only time will tell whether promised experimental results are forthcoming. But, on the basis of current neuroscientific understanding, does the proposal stack up? (continued)

  2. (continued)Unlike many tissues in our body, the nerves of the spinal cord don’t spontaneously repair themselves after damage. And despite regular media reports hailing new breakthroughs, currently there is no effective cure for the millions of people paralysed by spinal cord injuries each year.

    Polyethylene glycol is among a growing list of treatments (including drugs, stem cells and gene therapies) showing promise in pre-clinical studies, but the path to real-world applications is notoriously tricky.

    Experiments in animals such as rats and mice are essential to developing new therapies, but important differences must be borne in mind when extrapolating to human treatment. Given sufficient retraining, rodents – even with completely severed spinal cords – can learn to walk again, because much of their circuitry for locomotion is located below the injury.

    In contrast, the brains of primates such as monkeys and humans are more directly involved in guiding movements. As a result, the recovery experienced by people with complete spinal injuries is much more limited.

    For those that live with spinal cord injuries, there are some reasons for cautious optimism. A US trial of epidural stimulation is reporting impressive results using a small pacemaker-like device to send electrical signals into the spinal cord. Participants in the trial have been able to move their legs and even support their own weight while standing...

    Although epidural stimulation is a promising line of research, it is being trialled in a select group of patients and is still far from a magic cure. So, if we can’t yet mend an injured spinal cord, what hope do we have for joining the brain to an entirely new body?...

    Perhaps transplant tests with monkeys may in future provide convincing support for applying this surgery in patients, although such experiments would certainly not be allowed by the strict regulations that govern animal research in the UK. Nor should they be at present, given the severity of the procedure and slim chance of success.

    The media love stories about maverick scientists fighting the establishment. But science most often progresses in careful, incremental steps that are published and scrutinised in peer-reviewed journals. The philosophers can speculate whether it is better to be the donor or recipient of a brain transplant. But as a neuroscientist, until we have the technology to reconnect the spinal cord, neither is an appealing prospect in reality.

  3. To lend credibility to his fraudulent account of an execution, the pretentious Pooh-Bah in Gilbert and Sullivan's ''The Mikado'' sings:

    Now though you'd have said that head was dead

    (For its owner dead was he),

    It stood on its neck, with a smile well-bred,

    And bowed three times to me!

    For a century audiences have chuckled over Gilbert's whimsy, but last week, viewers of ABC's evening news watched something reminiscent of Pooh-Bah's story that was no laughing matter: a rhesus monkey's severed head, connected by tubes and sutures to the trunk of another monkey, and showing unmistakable signs of consciousness.

    The demonstration was an unsettling reminder that an organism, human included, is the sum of many mechanical and chemical parts that ordinarily work in concert but can be made to survive as disembodied entities...

    In the televised presentation last week of his handiwork, Dr. Robert J. White, a 72-year-old professor of neurosurgery at the Case Western Reserve University School of Medicine in Cleveland, demonstrated the grafting of the trunk of one monkey to the head of another in what he calls a ''whole body transplant.''

    Most of the experiments on monkeys, cats and dogs described in the broadcast were first conducted in the 1960's, but Dr. White believes the time is ripe for similar body transplants on humans. He acknowledged in an interview with The New York Times that reconnecting the millions of neurons bridging the brain with the spinal column is as yet impossible, and that a person (or rather, a head) who acquired a new body in this way would be paralyzed and insensible from the neck down. But the brain would retain its memory, its intellect, its perception of sight and sound, and its sense of self.

    ''For a quadriplegic who is already paralyzed, the main cause of death is generally the eventual failure of several organs,'' Dr. White said. ''If such a person were to be given a new body, it would be a new lease on life, even though he or she would still be paralyzed.''

    The transplanted heads of monkeys evince little tolerance of their executioners. ''You now have, as these animals showed, total capability of seeing, hearing and tasting. And if you get your finger too near the mouth of one of these animals, it will bite it off,'' Dr. White said.

    But what is it like to be a severed head?

    ''I happen to believe that what you and I are is basically within the 3 1/2 pounds of tissue between our ears,'' Dr. White said. ''I think the mind and soul are within the brain. I expressed that view to the Holy Father once, but I don't believe he was convinced.''