Head transplant

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A head transplant is a surgical operation involving the replacement of an organism's head with a replacement head. It should not be confused with another hypothetical surgical operation, the brain transplant. Head transplantation invariably involves decapitating the patient.

Since the technology required to reattach a severed spinal cord has not yet been developed, the subject of a head transplant would be a quadriplegic. This technique has been proposed as possibly useful for people who are already quadriplegics, and who are suffering from widespread organ failures which would otherwise require many different and difficult transplant surgeries. It may also be useful for people who would rather be quadriplegic than dead (for example because of progress in brain-computer interface). As of this time, there is no uniform consensus on the ethics of such a procedure.

1 Actual instances
2 Future and stem cells
3 See also
4 References
5 External links

[edit] Actual instances

The first head transplants were conducted in 1812, although they had only a marginal amount of success. There were many successive attempts on a variety of animals including rabbits and dogs. It wasn't until the 1970s that there was any real success.

In the 1970s a group of scientists from Case Western Reserve University School of Medicine in Cleveland Ohio, led by Robert J. White, a neurosurgeon a professor of neurological surgery who was inspired by the work of Vladimir Demikhov, performed a highly controversial operation to transplant the head of one monkey onto another’s body. The procedure was a success to some extent, with the animal being able to smell, taste, hear, and see the world around it. The operation involved cauterizing arteries and veins carefully while the head was being severed to prevent hypovolemia. Because the nerves were left entirely intact, connecting the brain to a blood supply kept it chemically alive. The animal survived for some time after the operation, even at times attempting to bite some of the staff. [1] In 2001 the operation was successfully repeated again on a monkey by the aforementioned Dr. White. [2]

Other head transplants were also conducted recently in Japan in rats. Unlike the head transplants performed by Dr. White, however, these head transplants involved grafting one rat's head onto the body of another rat that kept its head. Thus the rat ended up with two heads. [3]

The majority of neurosurgeons believe that head transplantation in humans will be possible in the near future.^{[citation needed]} The procedure would most likely involve cooling the brain to the point where all neural activity stops. This is to prevent neurons from dying while the brain is being transplanted. In any case, few authorities support the risky procedure. Still, supporters note that the brain, unlike the liver for example, is an immunologically sound organ; there is no risk of the new body rejecting it. Ethical considerations, however, have thus far prevented any reported attempt by surgeons to transplant a human being's head.

[edit] Future and stem cells

Through medical science it is now known that stem cells are capable of specializing into any type of cell found in the human body. In 1998 Fred H. Gage of the Salk Institute in La Jolla, California, showed the new, functioning neurons are indeed capable of being grown in the human hippocampus. Historically this was thought to be preposterous. The news gives a ray of hope for individuals suffering disabling diseases. Most believe the key to helping individuals whose bodies are incapable of sustaining them is not through arguably crude operations like a head transplant, but through stem cell research. However, the tenet of head transplantation may become more popular, as stem cells have been shown by the Wistar Institute of the University of Pennsylvania to repair the severed spinal cords of mice to a functional level. This could mean the subject would no longer be condemned to paraplegia.

However, should the technology to repair the damage to the spinal cord be developed, the possibilities of what a head transplant could accomplish will become endless. A disease such as cancer (non-brain) which afflicts an area of the body such as the lung or bladder, as well as other diseases such as diabetes which affects the pancreas and heart disease could be cured through the transplantation of the head. These diseases all affect the body but not the head. Should the head be transplanted these afflictions would be left behind in the old body while the new body enabled the head transplant recipient to live a longer healthier life. This would ultimately serve to improve the standard of living for the recipients, and could potentially double their life spans.