Showing posts with label Biomedical. Show all posts
Showing posts with label Biomedical. Show all posts

Thursday, May 19

Human Eyes After Death


Scientists have momentarily restored a faint twinkle of life to dying cells in the human eye.

In order to better understand the way nerve cells succumb to a lack of oxygen, a team of US researchers measured activity in mouse and human retinal cells soon after their death.

Amazingly, with a few tweaks to the tissue's environment, they were able to revive the cells' ability to communicate hours later.

When stimulated by light, the postmortem retinas were shown to emit specific electrical signals, known as b-waves.

These waves are also seen in living retinas, and they indicate communication between all the layers of macular cells that allow us to see.

It's the first time deceased human donor eyes have ever responded to light in this way, and it has some experts questioning the irreversible nature of death in the central nervous system.

"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 color," explains biomedical scientist Fatima Abbas from the University of Utah.

"In eyes obtained up to five hours after an organ donor's death, these cells responded to bright light, colored lights, and even very dim flashes of light."

After death, it's possible to save some organs in the human body for transplantation. But after circulation ceases, the central nervous system as a whole stops responding far too quickly for any form of long-term recovery.  READ MORE...