By: Esha Bagora

Media Production Editor

French neuroscientists from the Paris Brain Institute recently discovered that there is a wave of death that occurs at the end of consciousness, paving a path forward for other discoveries in the realm of dying and the associated brain changes. Neurobiology of Disease, a scientific journal, published a study which focused on observing rats to understand which neuron groups in their brains are most vulnerable during cardiac arrest. 

This particular study was built off of previous research that showed how prolonged oxygen deprivation leads to a sequence of brain activity changes involving ATP depletion, disruption of neurons, and a surge in gamma and beta waves. These waves are associated with creating conscious experiences.

A slow wave of death by anoxic depolarization occurs, leading to neuronal death in the cortex. Anoxic depolarization occurs in neurons during times of extreme oxygen deprivation, and it disrupts cellular functions. Anoxic depolarization also releases glutamate into the body — a neurotransmitter that can cause cell damage or death — and begins a slow-moving wave of death by sending massive electrical flows in the brain’s cortex. 

However, if the brain is rapidly re-oxygenated, a reversible process called a wave of resuscitation can occur, allowing for the recovery of brain functions. Researchers observed this wave of resuscitation in the rats when the researchers reoxygenated their brains, allowing the rats’ brain cells to replenish their energy reserves, essentially bringing them back to life. 

This study also identified specific neuron groups in the neocortex where the wave of death originates and observed its spread in two directions, suggesting vulnerability in deeper cortex layers during oxygen deprivation. Additionally, the researchers were able to pinpoint the neocortex layer in which the wave of death began at level 5 by recording the rats’ brain activity and then translating those findings to models of human brains. 

These findings advance understanding of neural mechanisms in the approach to death and may contribute to developing therapies and neuroprotective drugs for resuscitation during scenarios of oxygen deprivation, like heart and lung failure.

(Sources: Newsweek, Popular Mechanics, Neuroscience News)