Shares in US group Neuralstem skyrocketed before the weekend as investor excitement was ignited by news that its stem cells helped improve spinal cord injuries in trials with rats, potentially paving the way for trials in humans.

The group's stock surged more than 90% following the publication, in the journal Cell, of a independent clinical trial showing that its neural stem cells helped restore some movement in paraplegic rats.

In the study, neural stem cells were transplanted into the surgically transected spinal cords of six out of 12 rats, while the remainder received no treatment.

Those that did receive the transplant showed significant locomotor recovery, even regaining movement in all lower extremity joints, according to the company.

Taking a closer look, it was found that 57% of the grafted cells turned into neurons and, from these, "a remarkable number" of axons emerged, reaching both above and below the point of spinal injury. 

According to the firm, these axons expressed synaptic proteins in the host gray matter, suggesting they made synaptic contact with the host spinal neurons.

Reconnecting neurons

"This study demonstrates that our neural stem cells can induce regeneration of injured spinal cord axons into the graft and serve as a bridge to reconnect to gray matter motor neurons for many spinal cord segments below the injury," noted Karl Johe, Chairman of Neuralstem's Board of Directors and its Chief Scientific Officer. 

"The fact that these cells induce regeneration of axons and partial recovery of motor function makes them relevant for testing for the treatment of human spinal cord injury," he stressed.

A proposed human trial of involving Neuralstem’s stem cells and patients with spinal cord injuries was reportedly put on hold by US regulators in 2010.