Stories about scientists reanimating a brain in a jar, like those prompted by a paper published last week in Nature, have a long pedigree. In 1937 the Sunday Express reported “Lonely island experiments with machine that keeps a brain alive.” It went on: “In a guarded, walled laboratory… a machine is slowly being assembled [that] can even keep a brain alive after the animal it was taken from is dead.” The machine was allegedly being constructed by Nobel laureate surgeon Alexis Carrel (who bought the island retreat of St Gildas, off Brittany, with his prize money) and world-famous aviator Charles Lindbergh.
But the story was total fantasy, and so are any similar suggestions based on the new experiments. These were done at the Yale School of Medicine by a team led by neuroscientist Nenad Sestan. What they report is deeply interesting and rather surprising. Using an apparatus that “perfuses” brains with a blood-like fluid, pulsing it through the veins and arteries, they could see signs of tissue function in pigs’ brains taken from an abattoir—even though the pigs’ heads had been removed after the death of the animals up to four hours earlier. It has generally been thought that irreversible, debilitating damage of the cells and tissues of organs happens more quickly than this when blood circulation (and thus oxygen supply) is stopped, either by removal from the body or by death of the organism. That’s why people are pronounced brain dead minutes after the heart stops beating.
You can see where this is leading. Are we being too hasty to assume brain death in people who suffer fatal trauma? Might it even be possible to use a perfusion apparatus like this to keep brains alive—and perhaps even ultimately to transplant them to another body? Does the work offer hope for the many people (especially in Silicon Valley) who have paid large sums to have their heads cryogenically frozen after death, arresting cell decay, in the hope that one day they might be resuscitated?
The answer is a firm no. Despite breathless claims about “rebooting” or “bringing back to life” the pig brains, there is nothing in these experiments that gives any indication that a brain placed in the perfusion device could be brought back to conscious function. It’s not even a matter of this being “early days” for such a goal: it is very possible that, between seeing some activity in…