U.S. scientists have partially revived pig brains four hours after the animals were slaughtered. The limited rejuvenation of circulatory function and cellular metabolism in pig brains, which were harvested from animals slaughtered at a meat-packing plant, was achieved four hours after death by infusing the brains with a special chemical solution created to preserve the tissue.
A specially designed blood-like chemical solution tailor-made to preserve endangered brain cells. They were able to maintain the function of the cells for the next six hours.
In the future, BrainEx could be used to test how experimental drugs affect the wiring of a large brain or help researchers study the effect of brain injury on cells and neural connections, the researchers noted.
To prove that their system worked, the team carried out the experiment on around 300 freshly severed heads of pigs from a food processing plant around New Haven, Connecticut over a period of months.
"What we are showing is the process of cell death is a gradual, stepwise process".
Traceable particles were placed inside the brains of the dead pigs that could track the blood flow.
The pigs' brains, however, did not ever regain consciousness.
SCIENTISTS have brought pigs" brains back to life four hours after death - boosting hopes humans may one day return from "the other side'. While the researchers stress that BrainEx offers ample opportunities for scientific exploration in animal postmortem brains without restoration of brain circuit activity, they specify contingencies that would guard against crossing of ethical lines should any signs of such functions appear as the technology develops.
Researchers burned through hundreds of dead pig heads over a six-year period working to develop a technique - which they've christened BrainEX - to keep the brains supplied with oxygen, nutrients and other chemicals meant to halt their deterioration, because they were determined to study the organs in their original form.
However, the research team was quick to point out, none of these responses were close to what would constitute consciousness or awareness. Clinically, what they have is not a living brain but rather a cellularly active brain.
Experts writing in two articles also in Nature said the research opened up ethical conundrums - not least whether consciousness would have been recorded if the BrainEx fluid had not contained substances to block brain cell activity, and whether other methods were needed to assess consciousness.
Professor of medical ethics Dominic Wilkinson, who is also a consultant neonatologist in Oxford, said: "Once someone has been diagnosed as "brain dead" there is now no way for that person to ever recover".
"An important fact, since restoration of blood flow to the rest of the body (following a cardiac arrest, for instance), may activate injury processes in non-brain tissues which produce substances that damage the brain (for example, through activation of inflammation)".
The organ is the most complex structure in the known universe, but techniques such as freezing slices of the brain or growing colonies of brain cells in a dish do not let researchers explore the full 3D wiring of the brain.
Khara Ramos, director of the neuroethics program at the National Institute of Neurological Disorders and Stroke called for more thinking on ethical concerns and implications of these experiments. "For most of human history, death was very simple", Christof Koch, president and chief scientist of the Allen Institute for Brain Science in Seattle, said in a Nature article accompanying publication of the Yale study.
Stuart Youngner, a professor of bioethics and psychiatry, and Insoo Hyun, a professor of bioethics and philosophy, both at Case Western Reserve University School of Medicine, wrote in a separate commentary that such advances in brain resuscitation technology rekindle the debate around when medics should stop attempting to save a life and try to take organs for donation for another person's benefit. There may need to be "new rules", she said.