Scientists at Yale University claim to have successfully kept alive the brains of decapitated pigs for 36 hours.

Their research has garnered significant attention not only for its macabre methodology, but for the potential implications in humans as well.

Could our brains essentially be put on “life support” were something catastrophic or fatal happen to our bodies?

A living brain in a jar?

The research was described by Yale neuroscientist Dr. Nenad Sestan on March 28 at a meeting of the National Institutes of Health (NIH) and reported in the MIT Technology Review. Sestan told the publication that he didn’t intend for his presentation to become public.

Neither Sestan nor his assistant responded to multiple inquiries from Healthline.

According to the MIT Technology Review, Sestan and his team experimented on between 100 and 200 pig brains obtained from a slaughterhouse. Using a special apparatus known as BrainEx, they were able to circulate oxygen throughout the brains with a perfusion fluid.

The BrainEx system is a closed loop of tubes and reservoirs that pumps artificial blood that’s been warmed to body temperature into a brain. According to Sestan, the system resulted in the unexpected result of cells in the brain returning to a healthy state, capable of normal activity.

The technique is also likely to work in other species, including primates. “This is probably not unique to pigs,” he said during his NIH presentation.

The issue that many observers immediately seized upon was that if the “reanimated” brains returned to some modicum of functioning, would they also be conscious?

Disconnected from body and deprived of all sensory organs, would they wake up to some hellish limbo of existence?

The “brain in a jar” premise is a common one for medical ethicists, scientists, and philosophers to ruminate over.

“[It is] a fair example of the main core of true bioethics problems: the fragmentation and reassembly of basic life processes,” said Michael H. Shapiro, a professor of law and an expert in bioethics and organ transplantation at the University of Southern California.

Clearly seeking to assuage those fears, Sestan and his team claimed the brains showed no signs of consciousness. This was determined by using an electroencephalogram (EEG), a test that can detect brain wave activity, particularly those indicating thoughts and sensations.

What this means for people

Although still in its early stages, the significance of the research for humans is palpable, although likely not for life extension.

Instead, the BrainEx system, or one like it, that works on human brains could be used to better study things like Alzheimer’s disease.

“This is great for treating patients and preventing death and possibly reversing some injuries, but not for bringing the dead to life or ‘reanimating’ them,” Shapiro told Healthline.

“This research may expand opportunities for organ and tissue transplantation, and, possibly, allow some neurological improvement for brain-injured persons — e.g., by inserting tissue (including neuronal stem cells) to repair stroke or concussion-damaged brains,” he said.

Beyond these kinds of practical research, Shapiro is critical of the notion that brains might be kept alive and one day implanted into other bodies, like any other organ transplantation.

Others, however, are more willing to speculate.

“It may come to the point that instead of people saying ‘Freeze my brain,’ they say ‘Hook me up and find me a body,’” Dr. Steve Hyman, director of psychiatric research at the Broad Institute in Cambridge, Massachusetts, told the MIT Technology Review.

But there remain questions, both ethical and philosophical, about whether or not the brain can simply up and change bodies without serious effects to personality. Some argue that the brain is essentially inseparable from the body.

So, keeping a brain alive for transplantation is fundamentally different than, say, kidney transplantation, as some have compared it.

Shapiro explains that a person’s identity is “defined by the brain.”

“The brain and the kidney are both organs, but they cannot be assessed in the same way, because the brain is the seat of personhood and individual identity. It’s not just another organ,” Shapiro said.

Following a hypothetical brain transplantation, would the organ recipient be the same person before the operation? Or would they “become” the donor via the transplanted brain?

What does ‘brain death’ really mean?

Another ethical problem posed by Sestan’s work is how it potentially affects the legal definition of death. Brain death is a relatively novel concept in medicine and law, and still varies largely from one country to the next.

Unlike clinical death — defined by the stopping of certain biological functions, such as breathing and heart rate — brain death is a state in which an individual may still be physically alive but with little or no cognitive ability.

Reports — such as those of Jahi McMath, a 17-year-old girl who has been brain-dead since 2013 but nonetheless remains alive (even going through puberty) through the support of ventilators and tube feedings — raise serious questions about the definition of brain death.

Sestan’s work may also serve to further muddy the waters by giving hope to some that a brain, and therefore a person, might somehow be kept alive, even in the absence of a body.

Shapiro refutes such an apparently facile solution: ‘“Brains on life support aren’t persons and aren’t living brains.”

“A brain-dead person is no more alive for blood circulating in the brain than she is, because a ventilator is circulating blood throughout the body," Shapiro said of McMath. "Although tissue and organs may be useable (and might loosely be considered ‘alive’ for that reason), the person is still dead."