The human eye is a very complex organ. Part of its abilities is its complexity, but that’s the source of trouble, and studying the eyes is no easy task. This implies, for example, that the eye is one of the organs that cannot be transplanted. That may change one day, and that’s when a group of scientists realized that a deceased person’s retina cells are able to “see” light. The new study, published in the journal Nature, gives us new clues about life and death inside and outside of this unique organ.
Origin: Pork brain.
The origin of the study had to do with a previous experiment in which scientists managed to keep pig brains alive after they died. The scientists who led the experiment say it inspired them to try something similar on human eyes.
The human retina.
And that is that human retinas are both part of the eye and part of the central nervous system, so what was learned in the first experiment could be very useful. The eye study was performed specifically in the photoreceptor cells of the macula, the part of the retina related to central vision and color and detail vision. The experiment achieved its goal of “waking up” these cells after death, says University of Utah biomedical scientist Fatima Abbas, who authored the study.
What happens (in the eyes) after death?
The first tests succeeded in reactivating these photoreceptors, but the team wanted to go further, they wanted to make these cells communicate. For this, they had to ask themselves what happens to cells after death that do not allow them to function.
They discovered that hypoxia, or the lack of oxygen, was the phenomenon that affected the experiment. That’s why they worked to minimize the time between the death of donors and the study. With this they managed to record, for the first time in the eye of a deceased person, the signal emitted by these photoreceptors, called “Wave b”.
Between life and death.
Briefly resuscitated photoreceptors are neurons, adding a new dimension to study outside the field of view. The authors not only point out that the study may have applications in other areas of the central nervous system, but also challenge the current understanding of death as a process triggered by the irreversible loss of neuronal activity.
I give you my eyes.
Today it is not possible to transplant eyes, but this research may help improve retina transplants, a very limited procedure today. However, there is still a long way to go to get there. Perhaps these advances will alleviate the curious obstacles that patients with vision problems may face.
Improve eye study.
For now, the authors of the study emphasize that it will allow progress in the study of eyes and sight. A problem encountered by researchers in this field stems from the differences between the human eye and the eye of animals which are usually used for medical study. Additionally, brain death affects existing neurons in the eye, making it difficult to study the retina in human eyes. It can even help us understand a little better what lies on the border between life and death.