Stem cells hold the promise of differentiating in vitro (or ex vivo) large populations of specific functional cell types for therapeutic use from a self-renewing undifferentiated precursor cell. So far, scientists have been much better at isolating stem cells, such as hematopoietic, mesenchymal or even pluripotent embryonic stem cells, than they have at directing differentiation and developing products based on the technology. However, NeuralStem Biopharmaceuticals Ltd. believes it has achieved proof of principle in its application of CNS stem cells to neurological diseases.

"What we have done is we've cured the rodent version of Parkinson's disease," said I. Richard Garr, president and CEO. Garr said that dopaminergic neurons derived from the company's neural stem cells corrected rotational behavior deficits when transplanted into rats whose neurons had been killed. "What you've done is corrected one of the major behavioral deficits in this model, which is believed to be relevant to Parkinson's disease," he said.