Head transplant
Encyclopedia
A head transplant is a surgical operation
involving the grafting of an organism's head onto the body of another. It should not be confused with another, hypothetical, surgical operation, the brain transplant. Head transplantation involves decapitating
the patient. Although it has been successfully performed using dogs, monkeys and rats, no human is known to have undergone the procedure.
Since the technology required to reattach a severed spinal cord
has not yet been developed, the subject of a head transplant would become quadriplegic
unless proper therapies were developed. This technique has been proposed as possibly useful for people who are already quadriplegics and who are also suffering from widespread organ failure
s which would otherwise require many different and difficult transplant surgeries. It may also be useful for people who would rather be quadriplegic than dead. There is no uniform consensus on the ethics of such a procedure.
In 1963, a group of scientists from Case Western Reserve University
School of Medicine in Cleveland, Ohio, led by Robert J. White
, a neurosurgeon and 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.
Other head transplants were also conducted recently in Japan
in rat
s. 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. The scientists said that the key to successful head transplants was to use low temperatures.
A human head transplant would most likely require cooling of the brain to the point where all neural activity stops. This is to prevent neurons from dying while the brain is being transplanted. Ethical considerations have thus far prevented any reported attempt by surgeons to transplant a human being's head.
. 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 quadriplegia.
Should the technology to repair the damage to the spinal cord be developed, the possibilities of what a head transplant could accomplish would 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. People with genetic diseases such as muscle dystrophies whose bodies lose more and more functions over time, eventually leading to death, could benefit greatly from this procedure. 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 would enable the head transplant donor (not recipient, unless legal identity is carried with the body) to live a longer, healthier life. This would ultimately serve to improve the standard of living for the donors (or recipients) and could potentially double their life spans. Of course, the issue of immune rejection would, however, need to be addressed as always. Ethical concerns might well persist even if function could be completely restored to the patient: a brain dead person with a healthy body, suitable for head transplantation, is automatically in great demand as an organ donor. When used as a head transplant recipient, a body which might have prolonged and enhanced several lives is instead used for the benefit of a single person. Such an outcome will be unacceptable to health systems which suffer from a shortage of organ donors, or could suffer consequent to widespread adoption of head transplantation. Using, where possible, the functional organs of the diseased surplus body, may partially alleviate this concern.
In 1998 Charles Krauthammer of Time magazine warned of the potential medical future of head transplanting with cloning:
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
involving the grafting of an organism's head onto the body of another. It should not be confused with another, hypothetical, surgical operation, the brain transplant. Head transplantation involves decapitating
Decapitation
Decapitation is the separation of the head from the body. Beheading typically refers to the act of intentional decapitation, e.g., as a means of murder or execution; it may be accomplished, for example, with an axe, sword, knife, wire, or by other more sophisticated means such as a guillotine...
the patient. Although it has been successfully performed using dogs, monkeys and rats, no human is known to have undergone the procedure.
Since the technology required to reattach a severed spinal cord
Spinal cord
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
has not yet been developed, the subject of a head transplant would become quadriplegic
Quadriplegia
Tetraplegia, also known as quadriplegia, is paralysis caused by illness or injury to a human that results in the partial or total loss of use of all their limbs and torso; paraplegia is similar but does not affect the arms...
unless proper therapies were developed. This technique has been proposed as possibly useful for people who are already quadriplegics and who are also suffering from widespread organ failure
Organ failure
Organ dysfunction is a condition where an organ does not perform its expected function. Organ failure is organ dysfunction to such a degree that normal homeostasis cannot be maintained without external clinical intervention.It is not a diagnosis...
s which would otherwise require many different and difficult transplant surgeries. It may also be useful for people who would rather be quadriplegic than dead. There is no uniform consensus on the ethics of such a procedure.
History
In 1959, China announced they had succeeded in transplanting the head of one dog to the body of another twice.In 1963, a group of scientists from Case Western Reserve University
Case Western Reserve University
Case Western Reserve University is a private research university located in Cleveland, Ohio, USA...
School of Medicine in Cleveland, Ohio, led by Robert J. White
Robert J. White
Robert Joseph White was an American surgeon, best known for his head transplants on monkeys.-Biography:...
, a neurosurgeon and a professor of neurological surgery
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
who was inspired by the work of Vladimir Demikhov
Vladimir Demikhov
Vladimir Petrovich Demikhov was a Soviet scientist and organ transplant pioneer, who did several transplantations in the 1930s and 1950s, such as the transplantation of a heart into an animal and a lung-heart replacement in an animal. He is also well-known for his transplantation of the heads of...
, 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
Hypovolemia
In physiology and medicine, hypovolemia is a state of decreased blood volume; more specifically, decrease in volume of blood plasma...
. 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.
Other head transplants were also conducted recently in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
in rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s. 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. The scientists said that the key to successful head transplants was to use low temperatures.
A human head transplant would most likely require cooling of the brain to the point where all neural activity stops. This is to prevent neurons from dying while the brain is being transplanted. Ethical considerations have thus far prevented any reported attempt by surgeons to transplant a human being's head.
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 that new, functioning neurons are indeed capable of being grown in the human hippocampusHippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
. 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
Wistar Institute
The Wistar Institute is a biomedical center, with a focus on cancer research and vaccine development. It is located in the University City section of Philadelphia, Pa...
of the University of Pennsylvania
University of Pennsylvania
The University of Pennsylvania is a private, Ivy League university located in Philadelphia, Pennsylvania, United States. Penn is the fourth-oldest institution of higher education in the United States,Penn is the fourth-oldest using the founding dates claimed by each institution...
to repair the severed spinal cords of mice to a functional level. This could mean the subject would no longer be condemned to quadriplegia.
Should the technology to repair the damage to the spinal cord be developed, the possibilities of what a head transplant could accomplish would 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. People with genetic diseases such as muscle dystrophies whose bodies lose more and more functions over time, eventually leading to death, could benefit greatly from this procedure. 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 would enable the head transplant donor (not recipient, unless legal identity is carried with the body) to live a longer, healthier life. This would ultimately serve to improve the standard of living for the donors (or recipients) and could potentially double their life spans. Of course, the issue of immune rejection would, however, need to be addressed as always. Ethical concerns might well persist even if function could be completely restored to the patient: a brain dead person with a healthy body, suitable for head transplantation, is automatically in great demand as an organ donor. When used as a head transplant recipient, a body which might have prolonged and enhanced several lives is instead used for the benefit of a single person. Such an outcome will be unacceptable to health systems which suffer from a shortage of organ donors, or could suffer consequent to widespread adoption of head transplantation. Using, where possible, the functional organs of the diseased surplus body, may partially alleviate this concern.
In 1998 Charles Krauthammer of Time magazine warned of the potential medical future of head transplanting with cloning:
See also
- Experiments in the Revival of OrganismsExperiments in the Revival of OrganismsExperiments in the Revival of Organisms is a 1940 motion picture which documents Soviet research into the resuscitation of clinically dead organisms. It is available from the Prelinger Archives, and it is in the public domain. The British scientist J. B. S...
- Organ transplantOrgan transplantOrgan transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...
- Whole-body transplantWhole-body transplantA whole-body transplant or brain transplant is a hypothetical operation that would move the brain of one being into the body of another. It is a procedure distinct from head transplant, which involves transferring the entire head to a new body, as opposed to the brain only...
- Isolated brainIsolated brainIsolated brain refers to keeping a brain alive in-vitro. This is done either by perfusion by a blood substitute, often an oxygenated solution of various salts, or by submerging the brain in oxygenated artificial cerebrospinal fluid . It is the biological counterpart of brain in a vat...
- Frankenstein's monsterFrankenstein's monsterFrankenstein's monster is a fictional character that first appeared in Mary Shelley's novel, Frankenstein, or The Modern Prometheus. The creature is often erroneously referred to as "Frankenstein", but in the novel the creature has no name...