Researchers were able to reanimate dead eyes that were supplied by organ donors, in a breakthrough that suggests that even a brain death might not be permanent. Scientists in the US found that photosensitive cells in the retina of the eye could respond to light even up to five hours after death, sending signals “resembling those recorded from living subjects”.
These cells, also known as neurons, are a building block of the central nervous system (CNS) which includes the brain and the spinal.
This suggests that other similar neurons in the CNS could be similarly brought back to life.
Writing in the journal Nature, the authors noted that the study “raises the question of whether brain death, as it is currently defined, is truly irreversible”.
Lead author Dr Fatima Abbas, of the Moran Eye Centre at the University of Utah, said: “We were able to wake up photoreceptor cells in the human macula, which is the part of the retina responsible for our central vision and our ability to see fine detail and colour.
“In eyes obtained up to five hours after an organ donor’s death, these cells responded to bright light, coloured lights and even very dim flashes of light.”
In a previous 2019 study, researchers from Yale successfully revived the brains of 32 decapitated pigs.
The animals had been slaughtered four hours earlier, and scientists were able to turn on their blood circulation and metabolism, using a cocktail of chemicals.
However, in this latest test, the researchers went further, restoring b-waves which are the slow, rhythmic oscillations recorded in living brains.
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