Point of Death

Typically, death is understood as a complete and irreversible cessation of bodily functions, marked by the absence of a pulse, brain activity, and pupil reaction to light. However, defining death from a neurological standpoint proves complex. Emerging research suggests that the transition from life to death is not instantaneous but rather a gradual process that can extend over several minutes, characterized by intricate brain activity and, in certain cases, potential reversibility.

Previous Research

Oxygen is vital for life, and its absence leads to a state known as anoxia, where our bodies and brains suffer from oxygen deprivation. A prior study published in Frontiers in Neuroscience by researchers at the Paris Brain Institute revealed that during anoxic conditions, the brain undergoes a sequence of changes.

The brain stores adenosine triphosphate (ATP), its primary energy source. When deprived of oxygen, ATP levels plummet, disrupting neuronal function and triggering a massive release of glutamate—the main excitatory neurotransmitter in the brain.

Séverine Mahon, a neuroscientist at the Paris Brain Institute, noted, “Initially, neural circuits appear to shut down... but then we observe a spike in brain activity—particularly in gamma and beta waves, which are usually linked to conscious experiences. This may relate to near-death experiences reported by individuals who have survived cardiac arrest.”

Eventually, neuronal activity wanes until complete electrical silence is reached, indicated by a flat line on an electroencephalogram (EEG). However, this silence is interrupted by a high-amplitude wave termed “the wave of death,” resulting from neuronal depolarization—a process identified as “anoxic depolarization.” This phenomenon seems to trigger cell death within the brain's cortex.

Antoine Carton-Leclercq, another researcher from the Paris Brain Institute, elaborated, “This critical event, known as anoxic depolarization, leads to neuronal death across the cortex. It serves as a true marker of the transition towards the end of all brain activity.”

The wave of death is characterized by substantial electrical currents that spread throughout the cortex, extinguishing consciousness completely. Mahon and Stéphane Charpier, another study author from Sorbonne University, shared with Newsweek, “Recovering from such a cataclysm demands significant energy, leading to neuronal death in the aftermath of the wave of death. Previously, this wave was considered irreversible.”

Yet, the team discovered that the wave of death may not be as final as once thought. If oxygen is administered swiftly, the impacts of anoxic depolarization can be counteracted, leading to a phenomenon they termed the “wave of resuscitation,” which facilitates a gradual restoration of brain functions.

Understanding these two waves—the wave of death and the wave of resuscitation—offers profound insights into the dying process. However, like many scientific revelations, this one raises further questions. The researchers noted, “We knew it was possible to reverse the effects of anoxic depolarization if resuscitation occurs within a certain timeframe, but we needed to identify which brain areas are most susceptible to damage.”

To further investigate, the researchers aimed to locate the origin of the wave of death within the cortex and assess its spread.

New Research

The same team at the Paris Brain Institute, led by Séverine Mahon, published another study in Neurobiology of Disease in November 2023. This time, they induced respiratory arrest in rats to measure brain activity before, during, and after anoxic depolarization—specifically focusing on the wave of death.

They identified the wave of death's source within specific neuron groups in the neocortex, a region associated with perception, vision, hearing, and language. Notably, they found that the wave of death does not spread uniformly; instead, it travels upward and downward from the neocortex, moving slowly at a rate of only a few millimeters per minute. Mahon explained, “We observed that neuronal activity was initially consistent during brain anoxia, but then the wave of death emerged in pyramidal neurons within layer 5 of the neocortex, propagating in both upward and downward directions. This pattern has been consistently observed under various conditions, suggesting it may also occur in humans.”

While additional research is required to determine if similar processes occur in human brains, the findings indicate that deeper cortical layers may be particularly vulnerable to oxygen deprivation. Fortunately, the neuronal cells restored ATP levels once the rats' brains were reoxygenated, facilitating the repolarization of neurons and the recovery of synaptic activity—essentially reversing the death process.

These studies enhance our understanding of the mechanisms and brain activity alterations during death, revealing that the process is neither as abrupt nor as final as previously assumed. Nevertheless, every discovery leads to more questions. Stéphane Charpier, a co-leader of the research team, emphasizes, “We must now clarify the precise conditions under which these functions can be restored and develop neuroprotective treatments to aid resuscitation following heart and lung failure.”

Perspective Shift

Gaining deeper insights into the waves of death and resuscitation could revolutionize the medical field and potentially save countless lives. In doing so, we might see an increase in reports of experiences akin to near-death encounters.

What might these revelations entail? Even if we were to compile a comprehensive database of such accounts, the mystery of what happens after death may remain elusive—not to mention the ongoing debates regarding the origins of these experiences, such as the role of DMT.

Perhaps it's for the best that we remain in the dark about what lies beyond death. After all, even if we did uncover the truth, satisfaction would likely remain unattainable. Personally, my curiosity extends beyond death; I ponder whether our origins mirror our destinations. This, I believe, would be the next great inquiry to pursue.

This article was originally published in the author's newsletter, Curious Adventure, and was subsequently edited and republished on Medium with her permission.

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