Comment: Restoring cellular functions in pig brain after death

In a recent experiment, the brains of slaughtered pigs were partially revived several hours after death by pumping oxygenated artifical blood into the brains. Some low-level functions appear to have been restored, but the brains did not show any signs of consciousness. The results, published in Nature have been cautiuously welcomed by experts who see potential for new treatments for brain injuries and diseases, although they also raise many important ethical questions. We are a long way from being able to revive even the most basic human brain functions, however this new research has highlighted the need for continued debate as experts agree the definition of 'death' has not changed, however people who are declared "brain dead" are a major source of organs for transplant. OUCs Director of Medical Ethics, Professor Dominic Wilkinson says “If, in the future, it were possible to restore the function of the brain after death, to bring back someone’s mind and personality, that would, of course, have important implications for our definitions of death.  That might be possible one day.  But it is not possible now, and this research does not change that.” Read Professor Wilkinson's response in full below.

Full paper available here: Vrselja, Z., Daniele, S. G., Silbereis, J., Talpo, F., Morozov, Y. M., Sousa, A. M. M., Tanaka, B. S., Skarica, M., Pletikos, M., Kaur, N., Zhuang, Z. W., Liu, Z., Alkawadri, R., Sinusas, A. J., Latham, S. R., Waxman, S. G. and Sestan, N., (2019), 'Restoration of brain circulation and cellular functions hours post-mortem', Nature, Vol: 568(7752): 336-343

Prof Dominic Wilkinson, Professor of Medical Ethics, Oxford Uehiro Centre for Practical Ethics, University of Oxford, and Consultant Neonatologist, John Radcliffe Hospital Oxford:
 
“After someone dies, their brain normally deteriorates and disintegrates within a matter of hours.  This intriguing research demonstrated in pigs that it was possible to halt the progressive cellular damage that normally occurs in the tissue of the brain after death.  The researchers connected the disconnected brains of pigs, who had been dead for 4 hours, to a pump with an artificial preserving fluid, and showed that they could maintain some of the microstructure and even some of the cellular function for a period of up to 10 hours after the pig had died.  However, there was no evidence of return of global function of the brain.  The brains of the pigs remained electrically silent.
 
“What does this mean?  1. This research reminds us that ‘death’ is less an event, and more of a process that occurs over time.  Cells within the human organism may be alive for some period of time after the human person has died.
 
“2. This research might pave the way to important research using the human brain.  There are, obviously, real limits to the research that can be done on human brains – because of the risks to research participants.  However, research on brains after death is also limited – because brains normally deteriorate so quickly after someone has died.  This sort of technique might mean that someone could donate their brain to research after they had died, and researchers might be able to gain crucial insights into some of the microscopic structure and functions of the brain.
 
“3. This research might pave the way to future techniques to prevent deterioration in the brain – for example after a stroke or a head injury.
 
“4. More speculatively, it is possible that the research might lead to future techniques to attempt resuscitation of the brain after very severe damage.  However, we are a long way off from that.  The research did not show any evidence that their technique could restore meaningful function to the brain after death.
 
“5. At present we should be clear that this research does not have any implications for brain death or for organ transplantation.  Nor does it mean that there is a realistic prospect, any time soon, of bringing back people from the dead.  ‘Brain death’ refers to the irreversible loss of the capacity for awareness and consciousness.  Once someone has been diagnosed as ‘brain dead’ there is currently no way for that person to ever recover.  The human person that they were, has gone forever.
 
“If, in the future, it were possible to restore the function of the brain after death, to bring back someone’s mind and personality, that would, of course, have important implications for our definitions of death.  That might be possible one day.  But it is not possible now, and this research does not change that.”

Acknowledgement: reprinted from Science Media Centre.  More expert comments available on the Science Media Centre website.  

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