Pig brains restarted four hours after death: should brain death be redefined?



"The brain’s ability to revive its cells has been underestimated," said Nenad Sestan, a researcher at Yale University in the USA. He is one of the authors of a study resembling "a science fiction film," which was published on Wednesday in Nature. The researchers worked on 32 brains of pigs that had been dead for four hours. They irrigated these brains for six hours at 37°C – body temperature – with a special solution "designed to oxygenate tissues and protect them from degradation linked to interrupted blood flow". The results are impressive: "reduced brain-cell destruction, preserved circulatory functions and even restored synaptic activity".

 

The possibility of resuscitation from brain death is still a long way off since the researchers have not identified "any electrical activity that could be the sign of consciousness or perception phenomena". Nevertheless, although "this is not a living brain", it is "a celluarly active brain" explained Sestan.

 

The researchers hope that this discovery could "help improve understanding of the brain" by enabling post-mortem studies, and even pave the way for brain preservation treatment, "after a heart attack, for example". But the scope of the ethical questions raised is much broader: "It challenges our understanding of what constitutes a living animal or human being," said scientists commenting on the publication. The study challenges two principles on which there had previously been a consensus: "the fact that neural activity and consciousness permanently stop after blood flow is interrupted in the brain for a few seconds or minutes" and "the fact that unless blood circulation is rapidly restored, an irreversible process is initiated that leads to the death of cells and then the organ".

 

A wave of panic is also blowing among organ donation experts: "Most organs are removed from brain-dead donors. If we start considering this state as perhaps reversible, how are we to decide to remove organs? ".  Developing the BrainEx technique – a pump that irrigates the brain by stopping blood flow – could at the very least "harm organ donation" and could also challenge the very principle of organ donation.

 

For further reading:

Are organ donors really dead?

Disembodied pig brains kept alive artificially for 36 hours

In Switzerland, transplantation legislation changes the conditions for determining death


Sources: 

AFP (17/04/2019)

Photo : Pixabay/DR