researcher studying the force ofdeathon the brain have in conclusion describe the sequence of events that conduct up to the permanent cessation of neuronic activity . Not only do these findings drop luminousness on the strange phenomenon reported by multitude who have undergone close - decease experiences , but they could also leave to new medical intervention designed to revoke the physical process ofbrain death .
Until now , scientists have struggled to pinpoint the minute of intellectual expiration because , unlike the consistency , the brain does n’t just stop working in a individual minute . Rather , when oxygen supplies prevail out , nerve cell quickly deplete their stores of cellular fuel - roll in the hay as ATP - and become destabilized .
This triggers a massive release of the excitatory neurotransmitterglutamate , run to a burst of neural natural action as a somebody expire . “ neuronal circuits seem to keep out down at first … Then we see a upsurge in mastermind bodily function – specifically an increase in gamma and beta wave , ” explained study writer Séverine Mahon in astatement .
“ These moving ridge are usually relate with a witting experience , ” Mahon read . “ In this context , they may be imply innear - dying experiencesreported by multitude who have subsist cardiorespiratory check . ”
After a short while , this neural natural action fades to electrical silence – although even that is n’t the end of the storey , as the lifelessness is then dead interrupted by a in high spirits - bountifulness moving ridge that spreads across the brain , causing permanent functional and morphological change . Known as the " wave of death " , this phenomenon is get by neurons becoming depolarize in their last moments .
“ This vital issue , yell anoxic depolarization [ AD ] , induces neuronal death throughout the cortex , ” said study source Antoine Carton - Leclercq . “ Like a swan birdsong , it is the true marking of transition towards the cessation of all brainpower natural action . ”
fortuitously , this whole appendage can be reversed if the brain can be reoxygenated before the wave of death complete its oeuvre . However , until now , researcher did n’t know where in the brain this deadly rippling begins , or how it spread .
To investigate , the study author measure out electrical activity in the brains of dirty dog as they underwent AD . In doing so , they discovered that the wave of destruction begin in the excitatory neuron within the deep cortical layer , probably because these face cells have in particular high vigor demands .
However , when the researchers reoxygenated the lowlife ’ brains , the entire procedure was reversed as ATP stores became replenished and neuron became repolarized . “ We have observed this same dynamic under different experimental conditions and think it could exist in humans , ” said Mahon .
By tease out the measure that the brain go through in its net minute , the study author have evidence that death is anything but a clean-living cut , and that a person can potentially be institute back from the brink even after their brain activity readings haveflatlined . More significantly , by tracking the course of the " moving ridge of decease " , this workplace furnish novel insight into how to intimately protect the brains of patients who undergo cardiorespiratory failure .
The field has been issue in the journalNeurobiology of Disease .
