In a groundbreaking 2022 study published in Nature, researchers demonstrated that the human retina can still process light up to five hours after death, challenging long‑held assumptions about neuronal irreversibility.
Retinas, an extension of the central nervous system, consist of rods and cones that translate photons into electrical impulses. Using donated eyes, scientists recorded photoreceptor activity and found that these light‑sensing cells remained responsive for several hours after the donor’s death.
While photoreceptors stayed active, bipolar cells—the next relay in the visual pathway—rapidly lost function, mainly due to deoxygenation. By maintaining oxygen levels during eye transport, the team captured electroretinogram (ERG) signals indicating that bipolar cells could still fire, marking the first postmortem human retinal activity recorded in this way.
These findings suggest that similar oxygen‑preservation techniques could be applied to other neural tissues, offering new avenues for studying neurodegenerative conditions like Alzheimer’s disease. In vision science, the ability to keep retinal cells functional beyond death may improve the success of future retinal transplants for macular degeneration and other visual impairments.
While the concept of resurrecting brains remains a literary fantasy, the practical applications of this research could usher in a new era of neural preservation and regenerative medicine.
