Reviving Human Brains for Drug Testing
Recently, researchers have taken a controversial leap forward. After successfully reviving pig brains for experiments a few years back, they’re now diving into a new frontier: human donor brains. This team aims to restore functionality to these brains and use them to test experimental therapies.
Enter Bexorg, a biotech startup from Connecticut that spun out of Yale University. Their claim? They’ve developed a platform that taps into the vast, previously unexplored potential of the human brain.
“It’s a great brain bank.”
Unlike others who rely on simulated models, Bexorg is exploring actual mature human brains for extended periods. Their goal? To push forward research into treatments for various brain-related diseases.
Yet, beneath the innovative veneer lies an unsettling reality. The startup has conducted tests on over 700 human brains that suggest these brains are far from lifeless.
Bexorg takes freshly deceased brains, places them in a specialized vat, and supplies them with oxygen and blood substitutes via an artificial lung, draining waste through artificial kidneys. Tubes connect maintenance fluids to the brain through several ports.
This life support system, known as BrainEx, has been detailed in the peer-reviewed journal Science. It maintains core functions of the disembodied brains, allowing researchers to observe metabolic responses to various drugs.
Once a brain has been treated with anesthetics and left in a drugged state for about a day, it is then dissected into numerous pieces for further research.
Bexorg’s CEO, Zvonimir Vrselja, asserts that despite the drugging, these brains maintain some responsiveness to drug testing, though he acknowledges that higher functions do not return to normal.
A 2019 survey by Vrselja’s team indicated that the recovery of processes observed in revived pig brains after oxygen deprivation should not be interpreted as evidence of restored function. They saw no organized electrical activity associated with consciousness.
To keep these brain subjects from “waking up,” researchers use anesthetics, specifically propofol, to dampen electrical signals in the brain.
Bioethicist Brennand Parent shares concerns about the ethical implications of Bexorg’s work, stating the essential neural coordination for even minimal consciousness is notably absent.
Although Bexorg has implemented measures to inhibit neuronal activity, significant ethical questions remain. Yale bioethicist Stephen Latham noted that there’s practically no institutional oversight for this emerging research.
In late 2025, a study published in the journal Alzheimer’s and Dementia hailed Bexorg’s model as a groundbreaking tool that could enhance the success rates for developing Alzheimer’s treatments.
Bexorg did not respond to requests for comment regarding these developments.
Bruna Belaver, an assistant professor of psychiatry at the University of Pittsburgh, believes BrainEx represents a meaningful advancement over traditional animal models.
Collaborating with Bexorg, Bruce Carr, chief scientific officer at Biohaven, mentioned that results from using disembodied human brains could shave significant time off drug development processes, especially for promising treatments that fell short in animal tests.
MIT neuroscientist Li-Huei Tsai confidently remarked on the unique advantages of this “remarkable brain bank,” in comparison to his own research methods that utilize simulated brains from human stem cells.
