Dan Baumgardt: Neurosurgeon Sergio Canavero announced in 2015 that he would soon have the ability to perform the world's first human head transplantation procedure.
This would mean it will be possible to remove someone's head and transplant it onto one other person's neck and shoulders. So far, this has only been performed on cadavers, not living humans.
But suppose you would like to keep the face you have already got? Or perhaps you’re tired of the body you reside in? Would it ever be possible to change brains between bodies?
Emma Stone recently won her second Oscar for her role within the brilliantly surreal comedy Poor Things. In the film, Stone's character, Bella Baxter, receives a brain transplant from her surviving unborn child after committing suicide. The operation is performed by an experimental scientist, Dr. Godwin Baxter (played by Willem Dafoe).
Anyone who has watched the film will see Dr. Baxter remove the brain from the back of the skull, plucking it as easily as peas from a pod.
For reasons I’ll explain later, this scene shouldn’t be anatomically correct, nevertheless it begs the query – how feasible is it to perform a brain transplant? What are the sensible points of perhaps essentially the most difficult surgery ever invented?
Challenge one: entry and exit
The living brain has the consistency of sentimental pudding and is protected against damage by the skull. Even though it’s a tricky nut to crack, bone will probably prove to be the simplest structure to beat. Modern neurosurgical techniques use craniotomy saws to remove a part of the skull and gain access to the brain underneath.
It is value noting that not all neurosurgical operations reach the brain through this route. The pea-sized pituitary gland is positioned at the bottom of the brain, just behind certainly one of the sinuses behind the nasal cavity. In this case, it is smart to make use of a nose job as a substitute of pituitary surgery.
While the nose wouldn't be sufficiently big to place a brand new brain in, it could actually function a technique to remove it – if only in pieces. During the mummification process, ancient Egyptians, who considered the brain unimportant, removed pieces of it through the nasal passages.
Behind the skull, you reach the wrapping across the brain – three protective membranes, the meninges. The first, the dura mater, is hard. The second, aptly named arachnoid, resembles a spider's web, while the third pia is delicate and invisibly thin. It is these structures that grow to be inflamed during meningitis.
These membranes provide stability and forestall the brain from moving around. They also sort the insides of the skull into compartments. The first provides a protective cuff of fluid around the surface of the brain – consider gherkins floating in a jar of vinegar. Known as cerebrospinal fluid (CSF), it’s produced from filtered blood and is colorless.
The meninges also form channels between the brain and the skull. These are the routes that each blood and cerebrospinal fluid from the pinnacle return to the center.
Once the skull and meninges are opened, there will probably be enough of a window to remove the brain. This can be the best a part of the operation.
Challenge two: connecting the circuits
It's time to activate your latest brain. This is where things get complicated.
The brain receives sensory information from all around the body and sends instructions to it, causing muscles to contract, the center to beat, and glands to secrete hormones.
Removing the brain requires cutting 12 pairs of cranial nerves that come directly from it and the spinal cord. Information enters and leaves the brain through all of those structures. See the problem?
Nerves don't just reconnect. As soon as you chop them, they sometimes begin to crumble and die, although some are more immune to damage than others.
Research groups all over the world are experimenting with tips on how to promote the regrowth of nerve cells after damage to stop neurological symptoms. There are many ideas for achieving this, but they include using chemicals or transplanting cells that stimulate neuronal regeneration.
The researchers also suggested that a special biological glue might be used to reglue the 2 severed ends of a severed nerve or spinal cord back together.
Removing the old brain can even require cutting the arteries that offer blood. This can even cut off essential oxygen and nutrients, which can even require reconnection.
Challenge three: the aftermath
The final, most uncertain period is the aftermath. And the list of speculations is infinite. Will the topic regain consciousness? Will they have the ability to think? Move? Breathe? How will the body react to the brand new brain?
Most transplant operations require matching donors to recipients since the body's normal response to unknown tissues is to reject them. The immune system sends out a cavalry of white blood cells and antibodies to attack and destroy, convinced that this latest presence means harm.
Normally, brains are protected against this attack by one other shield, called the blood-brain barrier. If the donor's brain shouldn’t be reconstructed properly during surgery, it could be vulnerable to attack.
It's equally necessary to think about how your brain will react to your latest home. In “Poor Things”, it’s stated that Bella Baxter's brain and body are “not quite in sync”.
But brains can learn to grow. So, just as children gain an arsenal of thoughts, behaviors, skills and talents during their childhood development, a transplanted brain can do the identical.
So brain transplantation currently stays the stuff of science fiction and academy award-winning cinema. Feasibility in accordance with basic anatomy and physiology makes the event of such a fancy procedure unlikely. But will more time, tools, technology, expertise and naturally money make it profitable? If Poor Things offers insight into the ethics of brain swapping, it's a terrifying thought.
Dan Baumgardt, Senior Lecturer, School of Physiology, Pharmacology and Neuroscience, University of Bristol
This article has been republished from Conversation under Creative Commons license. Read original article.
Image Source: Pixabay.com
