Shares of a host of stem-cell companies rose Tuesday after researchers disclosed research showing that human cells helped regenerate spinal cord tissue in mice.

Shares of

StemCells

(STEM)

were up 18% to $5.82 on close to five times average volume.

Aastrom Biosciences

(ASTM)

shares lifted 7.3% to $2.50, and

Viacell

( VIAC) shares rose 5.5% to $5.33.

Scientists at the Reeve-Irvine Cancer Center at the University of California at Irvine said they were able to partially repair damaged spinal cord tissue in mice using human neural stem cells.

"This work is a promising first step, and supports the need to study multiple stem-cell types for the possibility of treating of human neurological injury and disease," said researcher Aileen Anderson.

Human neural stem cells helped mouse neurons form protective insulation and became new nerve cells forming connections with the mouse nerve cells, according to trial data.

In comparison with mice that received human cells that were unable to differentiate, those receiving human neural stem cells showed an improved ability to walk. The cells survived and improved walking ability for at least four months after transplantations, researchers said.

Human neural stem cells were provided by StemCells, and two of the company's scientists took part in the study, which was funded by the National Institutes of Health and the Christopher Reeve Foundation.