SKIN cells have been converted directly into brain cells in the lab for the first time.
A new technique avoids the usual first step in which adult cells must be switched back to an embryonic-like state before they can be redirected into different types of tissue.
Scientists said the research, carried out with mice cells, demonstrated the surprising versatility of adult cells. If it is replicated with human cells, it could aid medical research and treatment of degenerative brain and nerve diseases.
Marius Wernig, of Stanford University, said his team achieved the feat by adding three genes to the skin cells using a virus.
The result, within a week, was fully functional nerve cells, or neurons, that could communicate and make connections with other nerve cells. "They can do all the principal things that neurons in the brain can do," said Dr Wernig, whose study is published in the journal Nature. "We were surprised by both the timing and the efficiency [of conversion]."
John Rasko, head of cell and molecular therapies at Royal Prince Alfred Hospital, said the new approach was an important advance, because it might avoid one of the most feared side effects of using embryonic, or embryonic-like, stem cells to treat people – the development of cancer.
"It is hoped that these new cells might have applications in drug discovery and in therapies for neurological diseases including Alzheimer's, multiple sclerosis and spinal cord injury. But much work remains to be done before these promises can be realised in the clinic," Professor Rasko said.
Andrew Laslett, a CSIRO stem cell researcher, also stressed that safety testing needed to be carried out before its potential could be judged. But the fact skin cells could be converted to brain cells was scientifically fascinating, Dr Laslett said: "What they've done goes against all the biology I learnt [at university]."