Mice with Parkinson’s disease seem to improve their condition after receiving their own modified cells, a new experiment found.

Parkinson’s disease is a degenerative disorder of the central nervous system that often impairs the sufferer’s motor skills and speech. The disease robs about 1.5 million people in the U.S. of the ability to control body movements.

American and Japanese researchers converted skin cells from the tail of the sick animal into the dopamine-producing brain cells they lacked, and grafted the genetically matched tissue back into the same mice.

Before being injected with the stem cells, the mice had a number of behaviors common to their disease. They moved their paws in certain unusual ways and, when placed in a bowl, moved only in one direction. Normal mice move equally in both directions.

Once injected with the cells, mice’s behavior returned to normal. It was after the mice were killed, when the researchers discovered that the neural cells they’d injected had grown and formed connections with other cells.

“It demonstrated what we suspected all along -- that genetically matched tissue works better. When you give the other type of tissue, non-autologous tissue, you get more inflammation than we anticipated. This is in a lab animal where we expect it to be tolerant. Normally when you do this in mice, you don't give matched cells," said Viviane Tabar of Memorial Sloan-Kettering Institute in New York, who worked on the study, Reuters reports.


The researchers said although the procedure was technically complex and had only been carried out in animals, it could provide and effective way to avoid rejection of transplanted cells and treat a range of diseases in humans.

However, before this treatment can be tried on humans, scientists must learn how to make the cloning procedure work with human cells, a thing they weren’t able to achieve so far. They must also figure out how to keep human neural cells alive once they're transplanted. And this takes time, the researchers said.

“This is an exciting development, as for the first time, we can see that it may be possible to create a person's own embryonic stem cells to potentially treat their Parkinson's. Researchers in this area now need to carry out more studies to satisfy safety concerns and to make the process more efficient before these studies are carried out on people living with Parkinson's,” Dr Kieran Breen, director of research and development at the Parkinson's Disease Society said, according to BBC News

Professor Robin Lovell-Badge, an expert in stem cell research at the National Institute of Medical Research was skeptic about the study’s findings and said: “There was a very significant level of recovery. They only studied the mice for 11 weeks afterwards, which is not a huge amount of time to see how persistent the repaid would be.”

The findings were reported in the journal Nature Medicine.