“Scientists Are Giving Dead Brains New Life. What Could Go Wrong? In Experiments on Pig Organs, Scientists at Yale Made a Discovery That Could Someday Challenge Our Understanding of What It Means to Die”, 2019-07-02 (; similar):
In the course of his research, Sestan, an expert in developmental neurobiology, regularly ordered slices of animal and human brain tissue from various brain banks, which shipped the specimens to Yale in coolers full of ice. Sometimes the tissue arrived within three or four hours of the donor’s death. Sometimes it took more than a day. Still, Sestan and his team were able to culture, or grow, active cells from that tissue—tissue that was, for all practical purposes, entirely dead. In the right circumstances, they could actually keep the cells alive for several weeks at a stretch.
When I met with Sestan this spring, at his lab in New Haven, he took great care to stress that he was far from the only scientist to have noticed the phenomenon. “Lots of people knew this”, he said. “Lots and lots.” And yet he seems to have been one of the few to take these findings and push them forward: If you could restore activity to individual post-mortem brain cells, he reasoned to himself, what was to stop you from restoring activity to entire slices of post-mortem brain?
…The technical hurdles were immense: To perfuse a post-mortem brain, you would have to somehow run fluid through a maze of tiny capillaries that start to clot minutes after death. Everything, from the composition of the blood substitute to the speed of the fluid flow, would have to be calibrated perfectly. In 2015, Sestan struck up an email correspondence with John L. Robertson, a veterinarian and research professor in the department of biomedical engineering at Virginia Tech. For years, Robertson had been collaborating with a North Carolina company, BioMedInnovations, or BMI, on a system known as a CaVESWave—a perfusion machine capable of keeping kidneys, hearts and livers alive outside the body for long stretches. Eventually, Robertson and BMI hoped, the machine would replace cold storage as a way to preserve organs designated for transplants.
…By any measure, the contents of the paper Sestan and his team published in Nature this April were astonishing: Not only were Sestan and his team eventually able to maintain perfusion for six hours in the organs, but they managed to restore full metabolic function in most of the brain—the cells in the dead pig brains took oxygen and glucose and converted them into metabolites like carbon dioxide that are essential to life. “These findings”, the scientists write, “show that, with the appropriate interventions, the large mammalian brain retains an underappreciated capacity for normothermic restoration of microcirculation and certain molecular and cellular functions multiple hours after circulatory arrest.”
…”What’s happened, I’d argue”, says Christof Koch, the president and chief scientist at the Allen Institute for Brain Science, “is that a lot of things about the brain that we once thought were irreversible have turned out not necessarily to be so.”