Welcome to Unexplained Extra with me Richard McClane Smith, where for the weeks in between episodes, we look at stories and ideas that, for one reason another didn't make it into the previous show. In last week's episode, Death's Pale Flag, we explored the Haitian zombie myth through the seemingly miraculous
story of Clavius Narcis. In nineteen sixty four, Clavius was declared dead by two separate doctors and subsequently buried underground, only to reappear in his home village eighteen years later very much alive. Some, thanks to the prevalence of the zombie myth in Haitian folklore, were convinced that Clavius had himself returned from death as a zombie. In nineteen eighty two, ethnobotanist Weighed Dave traveled to Haiti to investigate Clerviius's story.
As it turned out, according to Davis, Clerviius was just one of many individuals who would have fallen victim to an apparent zombification process being carried out by voodoo priests in return for money. After analyzing a powder thought to have been used in this process, Wade found it to contain traces of tetrodotoxin, a potent neurotoxin extracted from pufferfish.
Although even a small dose of tetrodotoxin is lethal to humans, with just the right amount, its effects, including severe paralysis and the slowing of the body's metabolic rate, can lead the recipient appearing clinically dead before they eventually recover from it. Could this thought Wade account for Clerviius's apparent resurrection, regardless of what exactly had happened. That Clerviius could ever have been declared dead in the first place raises a deeply
un settling question. Just how exactly do we determine whether somebody has well and truly died. It may be surprising to discover that it isn't by any stretch an exact science. In years gone by, the death of a human individual was believed to have occurred simply when breathing had stopped or the heart was no longer beating. More recently, we have come to understand that absolute death comes only when
the brain has irreversibly ceased to function. However, it wasn't until nineteen sixty eight that a definition of brain death previously referred to as irreversible coma, was first formalized according to the Harvard Medical School Committee that to find it. The process for confirming brain death is fourfold. First, the body's responsiveness is taken into consideration, whether even the most painful stimuli failed to elicit a reaction. Next, the body
is monitored for signs of spontaneous movement and breathing. Does it require a ventilator to remain alive, for example. Thirdly, the body's reflexes will be assessed, most commonly by examining whether pupils respond to light or whether they are fixed and dilated. Finally, having taken all of that into account, an electroencephalogram or EEG should be used to test for any sign of brain activity. Only after all the correct criteria have been met could an individual be determined to
have well and truly died. Although this definition has been refined somewhat since nineteen sixty eight, with today's modern fMRI scanners a far more sophisticated way to measure brain activity, the basic process for determining the death of an individual remains more or less the same. And yet, just as we used to think that a stopped heart or final
breath was evidence of death. Might it also be the case that the criteria for supposed brain death could also one day prove to be an inadequate measure of a complete demise. Perhaps, just like in the days before we were able to measure brain activity, there might yet be some future more sophisticated technology to reveal the horrifying truth that brain death is in fact not a permanent, irreversible state. Could what appears to be a dead brain in fact
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teladoc dot com slash Unexplained podcast. In early twenty nineteen, a team of neuroscientists from Yale School of Medicine, led by its Vonomere vi Celia and Stefano Danielli, published a remarkable paper in Nature which, although not providing proof by any stretch that an individual might recover consciousness from a supposed brain death, has nonetheless reignited the debate over just what is or isn't irreversible. It is well understood that reducing oxygen and blood flow to the brain can have
rapid and devastating consequences. Just a few seconds without oxygen will result in a loss of consciousness. After five minutes a dino scene, triphosphate or atyp the body's primary source of cellular energy, will run out. If perfusion, the flow of blood and oxygen is not restored, a progressive and largely irreversible spiral of mechanical failure ensues from the build up of carbon dioxide to the emergence of enzymes that begin to break down the nerve tissue, which will lead
inevitably to the death of the brain. Although in the past, individual cells taken from brains long after death have been shown to continue to function, performing processes such as making proteins. What Vesselia and Danielli's team wanted to know was could a whole brain be revived a number of hours after death. To test this out, researchers collected thirty two severed heads of pigs that had been slaughtered in an abatoir close
to the team's laboratory. The brains, having been removed from the skulls, were then placed in a chamber and fitted with catheters. After waiting four hours from the moment of decapitation, each brain was given an EEG to confirm a flat line of brain activity before a warm substance containing nutrients and oxygen was slowly pumped into them. The system, known as brain X, developed especially for the experiment, is essentially a brain specific dialysis machine designed to mimic the original
host's blood flow. Although they didn't expect the brains to regain consciousness, the team used a chemical agent in the solution to reduce the possibility of this happening. With the solution cycling through the brains, all the scientists had to do next was stand back and wait. After six hours of tests, the results were startling. As an experiment to test the efficacy of the brain X system, things could not have gone better, as almost complete circulation was restored
to the brains. Blood vessels remained in such good shape throughout the experiment that they continued to function in the manner of a living brain. The system also succeeded in preserving the global structure of the brain. Tissue areas that are particularly susceptible to a lack of oxygen include the hippocampus, which plays a vital role in the consolidation of memories, were also well preserved. Comparing the solution as it flowed
to and from the brains. Research has also discovered signs of metabolic activity as individual cells began to function again, generating carbon dioxide while absorbing glucose and oxygen. But most striking of all, when small slices of tissue were tested after treatment, the team discovered that at least some neurons remained capable of neural activity, a process thought fundamental for generating consciousness. As the team from Yale were keen to stress,
their findings did not signify a resurgence of normal brain function. However, as others, including science journalist Sarah Reardon and the brain X team themselves have pointed out, since significant measures were taken to prevent this from happening, there is no knowing as yet what might have occurred under different circumstances, and even if the brain EX system was not enough to resurrect a consciousness from a dead brain, it would not be the end of the road for such a pursuit.
It may be the case that some additional, as yet unknown action might be needed to kick start this into life. After all, only in nineteen forty seven, thanks to the Maverick instincts of cardiac surgeon Claude Beck, was it confirmed that an electrical shock could restart a human heart. Certainly, it remains to be seen if an individual's sense of consciousness could be restored after their brain has been declared
clinically dead by today's standards. However, if history is anything to go by, that we haven't discovered yet how this might be achieved is no indication that it cannot be done, And with this comes some unsettling ideas just how much of a brain is required, or more specifically, how many of its constituent parts are necessary for a sense of consciousness and self awareness to emerge, even if we think not enough sections have been reactivated for this to occur.
Might the brain be able to construct modes of conscious self awareness that we are not yet aware of and therefore wouldn't even know if they had been activated or not.
And if, by some miracle it were possible to restore a sense of self awareness in a previously dead brain, whose self awareness would it be the individual that existed before death or something else, perhaps before we dismiss entirely the more alarming possibilities, As pointed out by the authors of a recent Comet piece about the remarkable brain X experiment, we might do well to ponder the wise word sub miracle Max from the nineteen eighty seven film The Princess Bride.
There's a big difference between mostly dead and all dead. Mostly dead is also slightly alive. If you enjoy listening to Unexplained and would like to help support us, you can now go to Unexplained podcast dot com, Forward slash Support. All donations, no matter how large or small, are massively appreciated. All elements of Unexplained are produced by me, Richard McClain smith. Please subscribe and rate the show on iTunes, and feel free to get in touch with any thoughts or ideas
regarding the stories you've heard on the show. Perhaps you have an explanation of your own you'd like to share. You can reach us online at Unexplained podcast dot com, or Twitter at Unexplained Pod and Facebook at Facebook dot com. Forward Slash Unexplained Now, it's time to take care of yourself. To make time for you, teledoc gives you access to a licensed therapist to help you get back to feeling
your best. Speak to a licensed therapist by phone or video anytime between seven am to nine pm local time, seven days a week. Teledoc Therapy is available through most insurance or employers. Download the app or visit teledoc dot com, Forward Slash Unexplained Podcast Today to get started. That's t e ladoc dot com, slash Unexplained podcast