If you are reading this article, you are certainly still alive. You know what life is like, that is when you control your body and your thoughts, you work and your nervous system works.
But what about death, what exactly is death, and what is death like?
This seemingly silly question is puzzling neuroscientists. One of them is Christof Koch, president of the Allen Brain Science Institute in Seattle, USA.
In an article titled "Can death be reversed?"Published in Scientific American magazine, Koch has struggled with the world's thoughts, research results and conventions to come up with a definition of death.
But he still failed. Turns out, death is more nuanced than you think.
Throughout history, people used to think they knew what death was. When someone stops breathing and their heart stops beating, that person is considered dead. Death is thus defined as a clearly delineated moment. Before that you lived, but after the last beating of the heart, you died.
But by the middle of the 20th century, everything had changed after the advent of ventilators and pacemakers. High-tech intensive medical care separates the heart and lungs from the brain, which is responsible for your mind, thoughts, and actions.
In response to these technological developments, in 1968, Harvard Medical School established a committee to come up with a new concept of death. They call it the irreversible coma – loss of brain function.
This laid the groundwork for a law in the US in 1981, which gave the unified definition of death an irreversible cessation of circulatory and respiratory functions or irreversible pause of function. brain power.
Very simply, when your brain dies, you are considered dead.
Not only used in the US, this definition is generally accepted in most advanced countries around the world. Thus, the location of death has been transferred from the chest to the brain. The time to determine death is no longer clearly delineated.
However, the fact is that most deaths still occur after cardiac arrest, which then stops all brain activity. Mental deaths usually occur only in the intensive care unit of the hospital (ICU), where there are patients with traumatic brain injury or deep coma.
These deaths are determined by irreversible coma, no reaction, brain stem or respiration.
At this point, brain death can be a decisive factor in defining the death of an entire human being. But it still can't replace the entire clinical diagnosis, because in fact, biological processes can still take place even when the brain has stopped working.
Indeed, a brain-dead body can be sustained for "living"with support devices for hours, days or even longer. For the relatives and friends of a brain-dead person, it's hard to understand what's going on.
When they arrived at ICU, they found that the patient's chest was still rising and falling, they felt the pulse, the skin was only a little pale compared to normal and the body was still warm. But their loved one lying there was actually a corpse, a corpse with a beating heart.
The body is only kept breathing and circulating, suspended between life and death, because they will be potential donors. With the consent of the family, the internal organs in the corpse will be collected for transplantation for those who need them.
Surprisingly, the body of the brain-dead person retains many physiological processes. They continue to grow nails, have periods, and some immune functions remain active to keep the body free of infection and decomposition.
Medical records document at least 30 cases of brain dead mothers during pregnancy are still on ventilators to maintain fetal life. After a few weeks, months, a record of 107 days, the fetus is still born and survives when the mother is brain dead.
In a story that attracted much attention in 2018, a young woman named Jahi McMath in New Yorker was able to maintain a home life at home for five years after brain death.
From a legal and medical perspective, McMath died 6 years ago. But for her loving family, she only passed away a year because of liver failure.
Going back to the best definition we now have of death, you can see its heart as the phrase "irreversible"As with the advent of ventilators and pacemakers in the 20th century, can we once again use technology to reverse the processes of brain death? If done, death again. will need to be redefined.
This leads us to a study just published in April this year, in which scientists were "revival"got a pig brain even though it died after 4 hours.
The study of revitalizing pig brains was carried out by scientists from Yale University, USA. In it, they collected 32 brains of pigs slaughtered at the slaughterhouse.
The scientists left the brain to die for four hours, after which they connected it to a system called BrainEx. This system consists of 3 parts: The first part helps to regenerate the pumping action of the heart. The machine will rhythmically pump a specially designed fluid, containing blood at 37oC, oxygen and drugs into the brain. Scientists say this has the effect of halting the process of cell death.
The second part of the system is also a blood circulation device, but pumps solutions that mimic the support organs around the brain, helping to reverse the process of cell death. The third and final part of BrainEx is a surgical procedure used to isolate the brain.
This revival process was carried out continuously by scientists at Yale University for 6 hours.
In a research report published in the journal Nature, the scientists say the brains have been dead for four hours. But after treatment with BrainEx, they reduced the rate of brain cell death, restored blood vessels and some functional activities.
One of the revitalized parts of the brain contains synapses. They are the pathways between different brain cells, allowing neurons to communicate.
The brain also displays a normal reaction to the drug, and uses the same amount of oxygen as a normal living brain to survive. All these records were drawn from observations at 10 hours after the pigs were beheaded.
The only absence of life for the pig brains in this experiment was brain waves, represented by zig zag EEG records you may already know. Scientists placed electrodes on the surface of these brains to see if they could pick up a signal.
But the answer is no. There are no slow waves marching on a piece of paper like when a person is sleeping, nor is there a single peak that jumps up abruptly. All is just a straight line representing the absence of "soul" and consciousness.
Even so, the team is not surprised. They themselves mixed a drug that inhibits nerve function into the circulating fluid of the brain. Because if the pig's soul returns, it will be a big trouble.
Not many people advocate bringing a "soul" back into a bodyless brain, and then having to kill it again, even if it's just a pig.
Despite this, they demonstrated the potential of this, by taking a small piece of nerve tissue from the pig's brain, rinsing the blood solution and then stimulating each individual nerve cell through an electrode. small. Some of these cells responded to this stimulus with one or a series of stereotyped electrical impulses resembling a complex nervous system.
This finding raises a profound question: What if the Yale team did not add neurosuppressants to their blood fluid?
Most likely, nothing happened. Just because some individual neurons maintain a stimulating response does not mean that millions of millions of neurons can organize themselves and operate to create a truly cognitive "soul".
But the story does not stop there. Nor can we exclude the possibility that some external stimulus, a type of brain defibrillator, for example, will restart these dead brains, as we use defibrillators to revive the fruit. heart.
This leads us to a situation where there is an elephant watching in the room. If we can develop such a medical procedure, should it apply to the human brain? Before someone wants to discuss this, think about some of the following situations.
What would you want to do if your child or wife was found to have drowned after hours, no pulse and no breathing? At this time, they are said to be dead. But the situation can be completely changed on the day when the type of brain resuscitation technology is successfully developed.
Its foundation could be Yale University's BrainEx system. Is that a goal worth pursuing?
The pig brain is a large brain, unlike mice, the most commonly used laboratory animals. The pig's brain has many folds like the human brain. Right at this time, neurosurgery procedures are still often tested on pigs before moving on to human trials.
So the technical answer is yes; In principle, we can pursue such a technology to revive the brain. But it's worth one thing, should we do it or not?
Koch's answer is no, based on scientific ethics. He would not advocate bringing a pig or even someone back to life with pain, disability or stress as a side effect of incomplete technologies.
But also according to Koch, not all scientists have the morality. Like the story of two genetically engineered girls being created in China late last year, when the field of brain revival goes far enough, at some point somewhere in the world there will be a scientist again. learn despite everything, cross the fine line to defeat the grim reaper.
It is hard to imagine the face of the god at that time, not knowing whether people will be more happy or sad on the day they retire?
Refer Scientificamerican, Washingtonpost