Dying Is a Long Process That Is Reversible; Starting Point of ‘Wave of Death’ Discovered
Dying is not as easy as turning an "on" switch to "off." Researchers have recently identified when the point of no return begins.
'Wave of Death' And Brain Dead
For the first time, researchers have pinpointed the location in the brain where the shutdown sequence starts when an organ is about to die. The beginning of what they refer to as the "wave of death" was found to be the brain's chemical flood, which was followed by an electrical wave and then nothing.
"Our work shows that dying (and not death) is not an event but a 'long' process that can be reversed up to a certain point," said lead author Séverine Mahon, a neuroscientist at the Paris Brain Institute in France. "But we don't yet know exactly where the point of no return lies."
In a new study, sedated mice were removed from mechanical ventilators while implanted instruments recorded the animals' experiences during their death and resuscitation. The somatosensory cortex, an area on the brain's outer layer that interprets information related to temperature, touch, texture, pain, and knowledge of one's body's position and movement in space, was examined for activity.
The somatosensory cortex's function, organization, and placement are identical in our brains. Scientists saw the initial wave of activity brought on by glutamate, a chemical messenger that promotes neuronal firing, as the rats died.
Massive glutamate release occurs when brain cells rapidly exhaust their ATP (the chemical that provides energy to cells) supply when they are oxygen-deprived.
According to Mahon, there is "a period of intense cortical activity" just before the brain flatlining. The brain waves associated with that surge are called beta and gamma waves and are typically connected to conscious experiences.
"We are aware that in healthy individuals, these brainwaves are accountable for memory recall," said Ajmal Zemmar, a University of Louisville neurosurgeon who was not part of the study.
Therefore, we are wondering if, at the moment of death, anything similar might occur: that is, after your heart stops beating and your brain is ready to die, you experience a memory recall.
However, Mahon noted that the patient was unconscious when it happened. She added that many believe the said activity is the cause of near-death experiences people reported.
They also propose an alternate hypothesis, suggesting that after successful resuscitation, near-death experiences happen during the slow recovery of brain processes that mirror those linked to hallucinations.
Scientists, however, cannot precisely describe the sensations associated with each stage of death. Zemmar says you can't ask that to someone after they pass away.
Brain activity plateaus after these enigmatic waves of activity. However, it's not over yet. This is when the "wave of death" occurs: as neurons shut down, a solid electrical wave travels across the brain.
Wave of Death Doesn't Mean Brain Is Dead
According to Zemmar's theory, the wave of death that started in layer 5 indicates that the brain may release these energy-hungry cells earlier to protect more crucial areas, such as cortical layer 2, linked to thought.
They restarted the rats' ventilators and continued to record electrical activity in various brain layers to determine whether brain function might be restored.
In contrast to what happened during the wave of death, the neurons in the dying brains repolarized when they were brought back to life.
The researchers discovered that as neurons repolarized, they produced brainwave fingerprints that suggested the likelihood that this delicate organ would regain function.
Per lead researcher Stéphane Charpier, it is now established that death is a physiological process that takes its time and is impossible to dissociate rigorously from life.
The brain is reportedly not always completely dead when there is a wave of death. To enable resuscitation in the event of heart and lung failure, they need to determine the precise circumstances under which these functions can be restored and produce neuroprotective medications, Carhpier added.
Restoring breathing in most situations can save a person's brain death if it happens four minutes after their heart stops. After that, like with the rats, various sections perish at varying rates.
Physicians can aid in slowing or halting this process if they can figure out how to stop the wave of death, either by focusing on the wave's source or limiting its spread.
The recent study is only the start of this investigation, but identifying the issue's origin is the first step in resolving it.
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