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A head transplant is a surgical operation which involves the grafting of one 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. ==History== As the book ''Stiff: The Curious Lives of Human Cadavers'' explains: In 1959, China announced they had succeeded in transplanting the head of one dog to the body of another twice. Dr. Vladimir Demikhov's work, among others, was deeply influential for the future science of organ transplant,〔Anna Claybourne, (What Are the Limits of Organ Transplants? )〕 as he pioneered many different forms of transplant in the 1940s and 1950s, including the use of immuno-suppressants.〔 His work was well known by other scientists and during the 1950s and 1960s, numerous heart transplants were performed on dogs in the United States by Dr. Norman Shumway of Stanford University and Dr. Richard Lower of the Medical College of Virginia. The first human heart transplant was performed by Christiaan Barnard in South Africa, in 1967, however, as they did not have the chemical agents to utilize immuno-suppressants, the patient receiving the transplant did not do very well. On March 14, 1970, 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. In 2001, Dr. White successfully repeated the operation on a monkey. White later wrote: In 2002, other head transplants were also conducted 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. The scientists said that the key to successful head transplants was to use low temperatures. The ability of fusogens like PEG and chitosan to rebridge a transected spinal cord has been confirmed by a 2014 German study: paraplegic rats recovered motricity within 1 month.〔Estrada, V., Brazda, N., Schmitz, C., Heller, S., Blazyca, H., Martini, R. and Müller, H.W., "Long-lasting significant functional improvement in chronic severe spinal cord injury following scar resection and polyethylene glycol implantation", Neurobiol Dis. July 2014, 67, pp.165-79.〕 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. In 2015, Italian neurosurgeon Sergio Canavero has said the procedure (head anastomosis venture) might be feasible – with improved technology and more accurate ability to keep neural tissue perfused – before end of 2017, which is when he intends to perform the procedure in either the United States or China.〔http://www.sciencedirect.com/science/article/pii/S0262407915603827 〕 A 30-year-old Russian with Werdnig–Hoffmann disease (type I spinal muscular atrophy) and rapidly declining health has volunteered to offer his head for the study.〔(【引用サイトリンク】publisher=Science Alert )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「head transplant」の詳細全文を読む スポンサード リンク
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