An international team from the US and Japan has managed torestore mice back to health from a condition akin to Parkinson's, by usingneurons which were grown in the lab and made from cloned skin cells from thesame mice.

Never before has a disease been treated successfully by usingcloned cells derived from the same animal that is being treated. Lorenz Studerclaims it to be a "proof of concept". He is the team leader of thisresearch, at the Sloan-Kettering Institute, New York, US. But he also warnsthat it is too premature to say whether this technique would finally apply tohuman patients as a practical therapy.

The mice were first given a drug that killed the neurons whichproduce the neurotransmitter dopamine. As a result, the mice developed movementproblems akin to those experienced by patients with Parkinson's disease. Theresearchers then took biopsies of the tails from these mice and sent them toJapan, to Teruhiko Wakayama, a cloning specialist.

Wakayama and his team created embryos by transferring skincells' nuclei into mouse eggs from whom the chromosomes had been already beenstripped. These Japanese researchers were able to create a total of 187embryonic stem cell lines from cloned embryos of twenty-four mice. Theseembryonic stem cells were then sent back to Studer's team in New York. Onreceiving the embryonic stem cells, Studer's team was able to coax them tobecome dopamine secreting neurons. These neurons were then transplanted intothe six mice having the symptoms of Parkinson's and who were given grafts ofneurons extracted from their own skin cells. All showed significant improvementand scored well in movement tests.