US scientists managed to bring brain cells of dead pigs back to life, which opens the possibility to recover the brain function after damage, and it opens the debate on the redefinition of death.
At an American lab, a group of scientists tries to bring back to life the brain of an animal. There is no more oxygen supply. It has been dead for four hours. Even like that, they manage to keep the cells alive and put a halt to their deterioration. Based on real facts. But this isn’t a script to a movie; it’s a real scientific breakthrough.
It happened in Connecticut, USA. This study was conducted by neurologist Nenad Sestand (University of Yale professor) and the results were published this Wednesday in Nature. The research was conducted on 32 pig heads from the meat-processing industry. The samples come from the quartering of pork-processing companies so no animals were sacrificed for this experiment. An ethical committee closely monitored the process.
In order to do it they designed a perfusion circuit that pumps a synthetic hemoglobin solution with oxygen, nutrients and cytoprotective drugs to an isolated, dead brain.
The device supplies, at room temperature, the necessary blood flow and repairs the effects of anoxia. They kept it this way during six hours (10 hours since decapitation). Furthermore, they developed a surgical mechanism to dissect a part of the bulky organ, conduct tests on it, conduct pathologic anatomy studies and verify the effect of the procedure, especially on the hippocampus, the zone that is most sensitive to hypoxia.
What they observed sheds light on the medical maneuvers of brain resuscitation. The internal architecture of cells remained intact, cell death was reduced, the molecular function, inflammatory response, vascularization, spontaneous synaptic activity and glia function were restored. In metabolic terms, the restored dead brain consumes the same oxygen and nutrients or releases the same amount of carbon dioxide than a living brain would.
Nevertheless, in the encephalogram, neither brain waves were observed nor consciousness signs. Having living cells doesn’t mean the brain function is correct. “It isn’t precisely a living brain but an active brain at the cellular level,” stated Nenad Sestand during a teleconference. “We were prepared with an anesthesia unit and a cooling unit in case we detected any vitals but that didn’t happen.”
Even so, researchers aren’t completely sure they can’t reactivate, in the future, the brain function, since in that synthetic blood solution they used a drug that blocks neuronal activity. This is part of the protocol and it ends here for the time being. In order to continue they need scientific and ethical consensus from the expert community. Giving life back to a dead organ “is an unexplored pathway” that requires, according to the authors, further neuroscientific knowledge before taking the next steps.
MEDICAL UTILITY IN BRAIN RESURRECTION
According to Julio Prieto, Head of the Clinical Neurophysiology Service at Hospital Gregorio Marañón in Madrid, “the work of Sestand and his collaborators opens a research pathway on postmortem brain metabolism and gets closer to the recovery of the brain function several minutes after hypoxia occurs, such as what happens with cardiac arrest,” he said to EL MUNDO.es.
“This could mean a revolution in the treatment of anoxic encephalopathy and it can also have implications in transplants,” noted Prieto. For someone in this situation, with a simple encephalogram, “being able to restore brain activity, we might be talking about someone who can get well and not about a potential donor,” he pointed out.
Sestand’s experiments don’t take the American scientific community by surprise. The paper came to light before being published at a National Institutes of Health meeting last March 28th, 2018. At this meeting Sestand announced he had managed to keep alive dissected brains of decapitated pigs for 36 hours. Since then, the ethical issues arising from this research are being discussed and many experts warn about the need to review the concept of death with the latest cardio respiratory reanimation and brain resuscitation breakthroughs.
James Bernat, active professor emeritus of Neurology at Dartmouth’s University (USA), analyzed the ethical aspects of this research as a part of the NIH BRAIN initiative committee. This expert has denied, in turn, that the most conflictive point of the study has been accomplished. “No global neurologic function could be restored as shown by the electroencephalogram or the electrocorticogram so there was no recovery of any of the integrated brain functions necessary to consciousness,” Bernat explained to this publication.
Therefore, according to Bernat, “this research shouldn’t have a direct impact in the practices of brain death declaration, which are described in terms of the irreversible halt of the brain function, not in terms of the irreversible halt of brain cellular activity.” But since it isn’t clear if in the future these techniques will allow for the recovery of any brain function, “this research can have implications for the emerging field of neuro-resuscitation after a severe brain injury if it can be proven that the intervention is safe in living individuals,” he concluded.
Date: April 17th, 2019
By: Mar de Miguel
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