Apr 30 2018
Keeping Brains Alive Outside the Body
Researchers at Yale report (at a meeting – not yet published) that they were able to keep pig brains alive for up to 36 hours after the pigs were decapitated. They acquired the pig head from a slaughterhouse, and experimented on them about 4 hours after death. This research is a long way from an alive “brain in a jar” but it does raise some early ethical questions.
First the technical stuff, with the caveat that the study is not yet published in the peer-reviewed literature so some details are sparse. We know the researchers experimented on pig heads. The report does not say explicitly whether the brains were completely removed from the skulls or not, but they did have access to the brain itself so it was at least exposed if not removed. They attached a series of pumps to the blood vessels and pumped oxygenated blood through them. They also used drugs to prevent the brains from swelling, and the researchers say these drugs would also prevent some brain cell activity (they are channel blockers).
They used brain-surface EEG to record electrical brain activity and – there was none. The pig brains were flat-line. But when they later dissected the brain tissue there was cellular activity for up to 36 hours.
This is clearly a baby step in the direction of maintaining a living brain outside of a body. Four hours after death is a long time, and there would certainly already be a lot of cellular death by that point. If the goal (and this wasn’t their goal) is to maintain a fully functional extracorporeal brain, then it would need to be hooked up to external blood flow within minutes of death, not hours. You can’t just get pig heads from the slaughterhouse.
But there is no theoretical reason why this would not work. If the brains were kept oxygenated throughout the process, and they were hooked up to an external system that fed oxygenated blood with managed CO2 levels and a supply of glucose (basically normal arterial blood), there is no reason why the cells could not survive for a long time. There are likely to be many technical hurdles here, but as a thought experiment it seems plausible.