Research shows that a "dead" brain can be revived, but there's a catch: this discovery has puzzled scientists.

About five years ago, neurobiologist Dr. Zvonimir Vrselja from Yale School of Medicine, along with his colleagues, shocked the medical community with an innovative experiment. During the study, they successfully extracted a pig brain from an animal slaughtered at a processing plant, deprived it of oxygen at room temperature for four hours, and then connected it to a resuscitation machine to revive it. The results of this research stirred the scientific community, as reported by Popular Mechanics.

It is known that the vascular system of a living brain, also referred to as the network of blood vessels, delivers oxygen-rich, nutrient-filled blood to the brain through arteries and capillaries. Therefore, in their study, the researchers utilized a specialized resuscitation device called BrainEx. With this device, they managed to pump a mixture of preservatives and medications into the deceased brain, targeting pathways that are typically damaged due to oxygen deprivation.

The authors of the study note that the mixture contained a blood substitute made up of molecules that balance the pH levels of cells, as well as medications that prevent excessive immune response and antibiotics.

What happened next astonished the scientists: the gray matter of the brain turned red, cells resumed protein production, and neurons began to show signs of metabolic activity, similar to that of living brains. In simple terms, the previously dead pig brain was now performing cellular functions again, but it was not conscious. According to Dr. Vrselja, what he and his colleagues discovered was quite extreme: the brain could not be labeled as fully "alive," but it also did not appear to be dead.

According to resuscitation, cardiac arrest, and intensive care expert Dr. Lance Becker, the outcome of this experiment contradicts everything science previously understood about death. Moreover, the scientist also stated that the world is essentially on the brink of a genuine paradigm shift, as we will have to reconsider what life and death truly mean.

Following the pig brain tests, Vrselja and his colleagues are now studying donated human brains with their BrainEx machine. This is a more delicate operation than the experiments with pigs and carries significant ethical implications.

During the pig brain experiment, the researchers ensured that no brain activity related to perception occurred. To achieve this, the team included sedatives in the formula to prevent electrical activity. They also concluded the experiment after six hours. However, experiments with human brains require greater caution.

According to biomedical legal expert Hank Greely from Stanford University in California, if a human brain were slowly approaching consciousness, it would spark debates from ethical, legal, and scientific perspectives.

Vrselja informed the publication that he and his colleagues "do not intend to connect anyone to their BrainEx machine at the moment of death." However, what they have achieved so far is a significant step towards proving that brain death may not be as final as we once thought. Meanwhile, the researchers have made certain progress in keeping the brain "cellularly active for up to 24 hours" so that they can test treatments for neurological diseases. They hope to assist patients suffering from conditions such as Alzheimer's and Parkinson's disease.