By Usama Abdul Karim.
A brain transplant or Head transplant is a procedure in which the brain or entire head of one organism is transplanted into the body of another organism. Theoretically, a person with complete organ failure could be given a new and functional body while keeping their own personality, memories, and consciousness through such a procedure.
Neurosurgeon Robert J. White has grafted the head of a monkey onto the headless body of another monkey. EEG readings showed the brain was later functioning normally. Initially, it was thought to prove that the brain was an immunologically privileged organ, as the host’s immune system did not attack it at first, but immunorejection caused the monkey to die after nine days. Brain transplants and similar concepts have also been explored in various forms of science fiction. For example an American actress Emma Stone recently won her second Oscar for her performance as a woman revived from the dead in the dark comedy “Poor Things”. In the film, Stone’s character, Bella Baxter, receives a brain transplant from her surviving unborn child after killing herself. The surgery is performed by experimental scientist Dr Godwin Baxter (played by Willem Dafoe).Anyone who’s watched the film will see Dr Baxter remove the brain from the back of the skull, shelling it as easily as a pea from a pod
A brief history of head transplants
Scientists have not attempted to transplant an isolated brain into any animal. The living brain is soft and squishy, and it is too easily damaged to attempt to scoop it out from one skull and plop it into another. Trying to transplant an isolated brain would also entail reconnecting numerous delicate cranial nerves, which would be challenging. The brain transplants that have been attempted are really head transplants.
The first attempt occurred in 1908, when scientists Alexis Carrel and Charles Guthrie transplanted a dog’s head onto another dog, creating a Cerberus-like animal that lived for just a few hours, according to a 2015 article in CNS Neuroscience and Therapeutics. This transplant gone unsuccessful, but Carrel and Guthrie’s work did contribute to medical science. Carrel was later awarded a Nobel Prize in Medicine for their work on blood vessel reattachment, a technique that would later lead to the possibility of organ transplantation and limb reattachment.
In 1954, Soviet scientist Vladimir Demikhov experimented with grafting dogs’ upper bodies to other dogs. The two-headed animals mostly lasted a few days, with one surviving up to 29 days, according to a 2016 review article in the journal . The grafted-on heads were functional, doing things like lapping up water and responding to visual stimuli. But immune rejection ultimately led to the dogs’ deaths.
In the 1960s and 1970s, an American neurosurgeon named Robert White took the head transplant concept a step further. Using rhesus monkeys (Macaca mulatta), he experimented with transplanting only heads, not full upper bodies, and did the transplants head-for-head, rather than grafting an extra head onto a full body, according to the 2015 CNS Neuroscience and Therapeutics paper. The transplanted monkeys could chew and swallow food and track objects with their eyes. They were, however, quadriplegic, because their spinal cords had been severed and could no longer send nerve signals to their bodies. They also died within about 36 hours due to troubles with blood flow.
Understanding Circuit Connectivity
Scientists have also made big steps in vessel reattachment and in theoretically keeping the blood supply to the brain flowing during a head transplant surgery. In 2015, researcher Xiaoping Ren, of Harbin Medical University in China, experimented with mice and reported a method of cutting just one of the two jugular veins in the neck and one of the two carotid arteries to connect a second mouse head to a first mouse body, leaving the other jugular and carotid to feed the original head.
But major problems remain. A big issue is that transplanting a head requires slicing and reattaching a spinal cord. Though Ren and his team have found ways to slice the spinal cord low enough in mice to enable the transplanted animals to breathe without a ventilator, there is no good evidence in humans that the spinal cord could heal, according to the History of Neurosurgery review. Some researchers are exploring nanomaterials and specialized polymers for spinal cord repair, but those methods have only been tested in animals with different nervous system physiology from humans.
Preventing the brain from losing oxygen during and after surgery would also be harder in humans than it is in mice, simply due to the size and logistics of moving around human body parts versus mouse body parts. There is little room for error: Brain cells begin to die within five minutes of losing oxygen, according to the National Institute of Neurological Disorders and Stroke.
For all these reasons, the Ethico-legal Committee of the European Association of Neurosurgical Societies (EANS) in 2016. (The committee has no legal power to stop head transplants from being performed, but produces professional guidelines for neurosurgery practice.)
Moving forward after connection
If we suppose the brain transplant has been done. So, Will the subject recover consciousness? Will they be able to think? Move? Breathe? How will the body react to the new brain?
Most transplant surgeries require donors matched to recipients, since the body’s normal reaction to unknown tissues is to reject them. The immune system sends a cavalry of white blood cells and antibodies to attack and destroy convinced this new presence means harm. Normally brains are protected from this onslaught by another shield, called the blood-brain barrier. If not properly reconstructed during the operation, the donor brain could be open to attack. It’s equally important to consider how the brain will react to its new home. So, brain transplantation currently remains the stuff of science fiction and academy award-winning cinema. But I think this is possible when we attach body to artificial head or brain to control the body until we will replace with original one and second thing is attachment of spinal cord vessels is important thing in head transplant.
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