Blind Mice Regain Sight After Cell Transplant

November 8th, 2006

Ann Arbor, Michigan - Researchers have shown in mice that retinal cells from newborns transplanted into the eyes of blind adults wire up correctly and help them to detect light.

The finding challenges conventional biological thinking, because it shows that cells that have stopped dividing are better for transplantation than the stem cells that normally make new cells.

For decades, researchers have sought a way to replace the light-detecting cells that carpet the back of our eyes - and which break down in diseases such as retinitis pigmentosa and macular degeneration. But they have struggled to find cells that will work normally after being transplanted into the eye.

To find the best cell type, researchers led by Anand Swaroop at University of Michigan, Ann Arbor, and Robin Ali at University College London, UK, extracted cells from the retinas of mice at various times when photoreceptors are normally being generated, as embryos and after they are born. They then injected these cells into adult mouse retinas and counted how many new photoreceptors were generated.

Cells produced in the few days after birth generated the most new photoreceptors after transplantation and connected to the retina correctly, they found. These cells were destined to be photoreceptors but had not fully matured into rods, the cells that detect low light. The results are published in Nature.

Injecting these cells into the eyes of partially blind mice improved the animals' sight, making their pupils react to light. "For us ophthalmologists it's very, very, very exciting," says Robert MacLaren, one of the study's authors at Moorfields Eye Hospital, London. "We can suddenly see in our minds a potential treatment."