Scientists announced Tuesday that they have successfully regenerated the spinal cords of paralysed rats using stem cells, a breakthrough that the researchers hope will lead to human trials.

Researchers built tiny patches of stem cells collected from rats and humans. They then placed the patches on the broken spinal cords of rats. With the patches, the rodents once again reached out and grabbed food with their paws.

Though scientists have been able to regenerate certain nerve cells from stem cells, this is the first time a crucially important set of nerves, called the corticospinal axons, have been grown.

The cells build a vast web of biological wiring, called the corticospinal projection, which sends information between the brain and the body.

They are crucial for voluntary movement in humans.

Conducted by scientists working in California, Wisconsin and Japan, the research was published in the journal Nature Medicine.

“The corticospinal projection is the most important motor system in humans,” said senior study author Mark Tuszynski of the University of California, San Diego. “It has not been successfully regenerated before. Many have tried, many have failed – including us, in previous efforts.”

The corrective patches were made from neural projector cells, a type of stem cell that can form multiple kinds of the different cells that comprise the central nervous system in humans and other mammals, including rats.

By using different chemicals, researchers were able to coax the neural cells into becoming useable spinal cord tissue.

“The new thing here was that we used neural stem cells for the first time to determine whether they, unlike any other cell type tested, would support regeneration,” Tuszynski said. “And to our surprise, they did.”

While creating corticospinal cells could likely help paralysed patients, the team behind the study believes it will be several years before they could start experimenting with the patches in humans. (Anadolu Agency)

•Photo shows scientist working in a laboratory.