Scientists have been able to partially revive the brains of decapitated pigs that died four hours earlier in a groundbreaking study.
Experts used tubes that pumped a chemical mixture designed to mimic blood into the decapitated heads of 32 pigs to restore circulation and cellular activity.
Echoing Mary Shelley’s classic novel Frankenstein, billions of neurons began acting normally and the deaths of other cells was reduced over the course of six hours.
Electrical brain activity across the brain associated with awareness, perception and other high level functions were not observed, however.
While the find is an exciting breakthrough, it is still a long way from proof that a person’s consciousness can be recovered after they die, experts caution.
But it may open the door to salvaging mental powers in stroke patients, however, as well as new treatments that boost recovery of neurons after brain injury.
A research team led by Yale School of Medicine obtained the pigs’ brains from abattoirs and placed them in a system they created called BrainEx.
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Bringing a person back from the dead may have moved a step closer after scientists were able to restore the cells in the brains of pigs that died four hours earlier. Experts uses tubes that pumped a chemical mixture designed to mimic blood into the decapitated heads of 32 pigs to restore circulation and cellular activity
Echoing Mary Shelley’s classic novel Frankenstein, billions of neurons began acting normally and the deaths of other cells was reduced over the course of six hours. This image shows inactive brain cells ten hours after death (left) and cells that were active after the same duration having been hooked up to the system (right)
HOW DOES BRAINEX WORK?
BrainEx involves connecting a brain to a closed loop of tubes and reservoirs.
These circulate a red perfusion fluid, which is able to mimic bloody by carrying oxygen around the brain.
That includes to the brain stem, the cerebellar artery, and areas deep in the centre of the brain.
The system can regulate circulation of the synthetic blood around a mammalian brain.
In this case researchers were working with pigs, but they have previously stated any species could be hooked up to the machine – including primates.
Past studies saw the machine used to keep hundreds of pig brains alive outside of their bodies for up to 36 hours.
It mimics pulsating blood flow – known medically as perfusion – at normal human body temperatures of 37°C (98.6°F).
The team saw a reduction in the death of the brain cells over the course of six hours.
There was also revival of some cellular functions, including the firing of synapses – vital connections between neurons that transport signals.
The study suggests some brain activities have the capacity to be restored at least partially – even a few hours after death.
It also challenges long-held assumptions about the timing and irreversible nature of death, say the researchers.
Senior author Professor Nenad Sestan described the results as ‘mind-boggling’ and ‘unexpected’ but believed the technique could work on humans.
Professor Sestan, a neuroscientist at Yale, said: ‘The intact brain of a large mammal retains a previously underappreciated capacity for restoration of circulation and certain molecular and cellular activities multiple hours after circulatory arrest.’
Electrical brain activity across the brain associated with awareness, perception and other high level functions were not observed, however. This image shows what happened when scientists pumped chemical solution into dead pig’s brain
Although there was no evidence of global network activity or full-brain function during the experiments.
But many basic cellular functions – once thought to cease seconds or minutes after oxygen and blood flow stop – were observed.
Cellular death within the brain is usually considered to be a swift and irreversible process.
Cut off from oxygen and a blood supply, electrical activity and signs of awareness disappear within seconds – while energy stores are depleted in minutes.
Current understanding maintains a cascade of injury and death molecules are then activated leading to widespread, irreversible degeneration.
But researchers in Professor Sestan’s lab – who focus on brain development and evolution – found that small tissue samples routinely showed signs of cellular viability.
This was the case even when they were harvested many hours after death.
While the find is an exciting breakthrough, it is still a long way from proof that a person’s consciousness can be recovered after they die, experts caution. This image shows magnetic resonance imaging scans of the brains
It may open the door to salvaging mental powers in stroke patients, however, as well as new treatments that boost recovery of neurons after brain injury. This image shows an analysis of synaptic organisation, neuronal activity, and wider brain activity
A research team led by Yale School of Medicine obtained the pigs’ brains from abattoirs and placed them in a system they created called BrainEx that mimics pulsating blood flow. This image shows the restoration of brain circulation and cellular functions hours post-mortem
Intrigued, they used the pigs’ brains to discover how widespread this is.
Four hours after death they connected up the blood vessels to circulate a uniquely formulated solution they developed to preserve the tissue using BrainEx.
They found brain cell integrity was preserved and certain neurons, glial cells found in the central nervous system, and blood vessel cells, began working.
The breakthrough may also shed light on the structure and function of the human brain – which is difficult to analyse.
This hinders investigations into topics like the roots of brain disorders as well as neuronal connectivity in both healthy and abnormal conditions.
The chemical solution used lacks many of the components found in human blood – such as the immune system and other cells.
This makes the experimental system significantly different from normal living conditions.
Any future study involving human tissue or possible revival of global electrical activity in ‘dead’ animal tissue should be done under strict ethical oversight, the researchers said.
‘Death is a process and it takes time, not just seconds or minutes – we knew that,’ said Dr Martin Monti, associate professor in the departments of psychology and neurosurgery at the University of California Los Angeles, who was not involved in the research.
‘The advance here is that, with the right technology, we might now have more time to recover some molecular, cellular, and microvascular function before these are completely compromised in the non-human animal model, a prospect which might some day extend the potential timeline for restorative interventions in human tissues.
‘However, this should not be confused with acts of magic restoring any function in one’s favourite long-gone hero, which is not going to happen any time soon, and it should also not be confused with re-infusing cognitive processing or, much less, sentience in the decapitated head.’
The full findings of the study were published in the journal Nature.