A head transplant is a procedure in which the head of a subject is severed and placed upon another body. It should not be confused with a brain transplant, a hypothetical procedure in which a brain is transferred from the skull of one individual to another. As of the first part of the 21st century, this form of surgical grafting has never been performed on humans. Head transplants in animals have, to some degree, been successful.
The first attempted head transplant in animals was performed in May 1908 by Charles Guthrie of the United States. Guthrie grafted the head of a puppy onto the side of a full grown adult dog’s neck. The arteries in the neck and head of the puppy were grafted to those of the adult dog so that blood successfully flowed through both heads. While some movements and reflexes of the second head were recorded, too much time had elapsed between decapitation of the head and restored circulation for the brain of the second head to function properly.
Other, more successful, head transplants were performed on animals in the years to follow. In the early part of the 1950s, Vladimir Demikhov of the Soviet Union developed a method to reduce the amount of time the severed head was deprived of oxygen through the use of “blood vessel sewing machines.” Experiments that followed included both a head transplant of a dog by scientists in China in 1959, and a highly controversial head transplant of a monkey performed in 1963 by a group of researchers in Cleveland, Ohio. This head transplant was somewhat successful in that the monkey maintained its senses of smell, taste, hearing, and sight. Further head transplants involving rats have also occurred in Japan.
The transplant of a human head would require highly advanced technology that would include cooling the brain of the secondary head to the point that all neurological activity ceases. This would be necessary in order to prevent the death of neurons in the brain. Technological advancements have not yet made it possible to successfully graft a detached spinal cord. Thus, the subject of a head transplant would not have use of the limbs of the body and would be quadriplegic. It has been proposed that this surgical procedure could be beneficial to individuals who are suffering from multiple organ failures and are already quadriplegic, or would prefer to live a life without the use of limbs.