Can you transplant a head to another body?

On March 14, 1970, Robert White and his team brought two small monkeys into an operating room. White, a neurosurgeon, was about to embark on an ambitious experiment that had been decades in the making, one that seemed almost surreal. His objective was to connect the head of Monkey A to the body of Monkey B, essentially performing what he termed a whole-body transplant. His ultimate aspiration was to conduct this procedure on humans one day.

The concept of a body transplant is unsettling and raises numerous ethical, biological, and philosophical questions about the nature of life and the limits of science, questions that continue to be debated today. The primary question, however, was whether such a surgery was even medically feasible. White's experiment faced significant technical challenges. One major issue was the certainty of paralysis, as no doctor at the time, nor since, has been able to reconnect a severed spinal cord.

White, however, believed the surgery could be life-saving for patients with spinal cord injuries or progressive diseases like ALS, who often experience multi-organ failure and paralysis. He hoped that a body transplant could save their lives by replacing all their failing organs simultaneously.

But paralysis wasn't the only obstacle. Brain cells, with their high energy demands, require a constant supply of oxygenated blood. The transplant surgery would likely interrupt the brain's oxygen flow for hours, risking severe damage. White proposed a solution: cooling the brain to slow its metabolism and reduce its oxygen needs. Through experiments on dogs and monkeys, he developed a technique to selectively chill the brain's blood flow while keeping the rest of the body's blood warm and circulating.

In 1964, White successfully applied this brain-cooling technique on a human patient with a life-threatening brain tumor, cooling the brain to "suspended animation" at 11°C. This procedure extended the safe operating time from just 3-5 minutes to over an hour, revolutionizing neurosurgery and bringing White closer to his goal of a body transplant.

However, the ethical implications of such a surgery were significant. It raised questions about what conditions might justify such an experimental procedure, which could result in debilitating pain and neurological damage. The potential harm to animals in proving the technique's viability was also a concern. Bioethics was still an emerging field at the time, yet many critics, including members of the scientific community, condemned White's research as cruel. Despite this, he continued to receive approval from agencies like the NIH and was ready to attempt a monkey body transplant by 1970.

In the procedure, temporary blood vessels—plastic tubes—were used to connect the head of Monkey A to the body of Monkey B. When the monkey awoke from anesthesia, it was alive but paralyzed and highly distressed. It could see, smell, hear, and even attempted to bite a doctor's finger. White considered this a success, demonstrating that the brain could survive a head transplant and, with high doses of immunosuppressive drugs, could avoid rejection.

This surgery raised profound questions about the mind-body connection. Modern neuroscience supports the brain's central role in consciousness, but discoveries about gut neurons and the microbiome suggest the relationship may be more complex. Does part of the "self" reside outside the brain? The body and brain are interconnected by numerous circuits and signaling systems, raising the question of what is lost when they are separated.

White retired in 1998, having performed over 10,000 brain operations but never achieving his dream of a human head transplant. Nonetheless, his work continues to inspire debate and interest among scientists. If a doctor could successfully attach a patient's head to a donor body, the question remains: which of the two would emerge? And is extending a life always worth the cost ?

Credits : TED-ed Youtube video, Max G. Levy