Why Can't We Transplant Brains?
Two days before Christmas Day in 1954, the first organ transplant was achieved when a kidney was transplanted from a man called Ronald Herrick into his identical twin, Richard, at a hospital in Boston. In 1963, the first human lung transplant was performed at the University of Mississippi. The liver transplant came next in 1967, also in the U.S., and that same year a heart was transplanted at a hospital in Cape Town, South Africa. We can now transplant other organs, such as the pancreas, intestine, and thymus, with the kidneys, liver and heart being the most frequently transplanted organs. Tissues can also be transplanted, and right now scientists are even working on ways to 3-D print human tissue. But there’s one things humans haven’t cracked, and that’s the organ that makes us more us than any other. Today we’ll find out why, in this episode of the Infographics Show, Why Can't We Transplant Brains?
First of all, we should look at what the brain actually does. This thing inside our skulls that weighs on average about 3.3 pounds (1.5 kilograms) is larger in humans than any other vertebrae when compared to body weight. That’s why we are so brainy. The busy brain is our command center for our nervous system, which takes in data from our body and gives directions to our muscles. In fact, it does so much work, it requires about 20 percent of our energy to run it. When we are brain dead, we no longer have any neurological activity. With the help of machines, we can be kept alive for a short time, but within a week the body will not be able to function. While we may still be alive in some sense for that week, we are technically dead when the brain is dead. Some good news is that during the time we are kept alive, some of our other organs can be donated. But why can’t we accept someone else’s brain?
When we transplant something such as a heart, surgeons use a mechanical pump to keep blood flowing through the body while the new heart is being put in. The new heart is connected to the major blood vessels, and this might take several hours. You’ll stay in the hospital for one to two weeks, and if your body doesn’t reject its new heart, it’s said 87 out of 100 people make it through the year, and 60 out of 100 get through another decade. So, wouldn’t it just be possible to open the skull and connect a new brain where the removed brain was connected?
This question was asked to a Professor of Neurosurgery at Yale in 2013. He actually did say that one day this operation might be successful, but right now we are not even close. The reason is because it’s just too darn difficult to connect nerve fibers from the new brain to the native spinal cord. This, he said, is why spinal cord injuries can be so devastating. If we could transplant brains, we would likely not have so many people that are disabled due to spinal injuries. Another Professor of Neurosurgery, speaking in the same article, said that what might be more feasible is a whole body transplant, which means a healthy brain being given a new body, which could be natural or artificial.
We dug a little deeper, and found that indeed some fairly amazing transplants have been done with brains or heads. In the 1950s, Russian scientist Vladimir Demikhov created what has been called Frankenstein’s dog, when he transplanted the head of one dog onto another, giving it two heads. Later, American scientist Robert White controversially transplanted the head of monkeys, from one to another, but the monkey was paralyzed as its spinal cord had been severed and it died in a few days. Basically, you can transplant a brain or a head, but doing it successfully is going to be a problem. She believes that we won’t even go there because it is just too gruesome and the public won’t like it. Everyone seems to come to the same conclusion, in that if you sever the nerves in the central nervous system, the transplanted brain could not be reconnected. All the neurosurgeons out there seem to agree, that we just do not have anything near the technology to reattach the brain’s veins and cranial nerves, the spinal cord, and the four major arteries. One particular scientist paints a very bleak picture, wherein we successfully attached a brain to the arteries and veins. You’d be thinking, but according to him, “You'd have a person in utter sensory isolation and paralysis—Locked-in syndrome only worse.” He believed a full head transplant would be easier. By the way, you might have read that an Italian neurosurgeon called Sergio Canavero performed a head transplant recently, but that transplant wasn’t on living people, it was on corpses. We are not Lego; just sticking things together doesn’t mean they work with us humans. For the most part, the great head transplant story is now being received as fake news.
So, with billions of neurons each with trillions of synapses in the cerebral cortex, we can’t really just expect to hook a new brain up to another body. But never say never; while brain transplants might sound like science fiction, what might happen if we did successfully manage to rewire a brain in another body?
No one really knows, but there is a lot of speculation out there. It seems some people agree you’d just be you, in another body. By that, you’d be the brain in another body, and the person whose brain was removed, while looking like the survivor, would in fact be the person who had gone. The brain rules. Another thing people talk about is the fact that brains grow with bodies, in tune, so if one brain was put in another body, things might not just run like clockwork. It could produce a kind of trauma, even if all the right bits were connected. And that could only happen if the huge doses of immunosuppressants could ensure the immune system doesn’t attack the new brain, or head. Even if you did do that, one scientist said this year that by putting a new chemical environment with new neurological input would just lead to a very mentally messed up Frankenstein. We’d have no continuity, and might end up feeling like Mary Shelley’s creation who once asked, “Was I, then, a monster, a blot upon the earth, from which all men fled and whom all men disowned?”
In conclusion, we are not even close to brain transplants, or head transplants. We are not sure how they could be done successfully, and we are very afraid of trying. What do you think about the idea? Let us know in the comments! Also, be sure to check out our other video called Worst Prison Experiments Conducted on Humans!