Spinal cord injuries can be profoundly life-altering for those who suffer them, but a significant advance may have been made by researchers at the University of California, San Francisco. As detailed in a new paper, published in the journal Cell Stem Cell, investigators were able to transplant human neurons into mice with spinal cord injuries — and found that the cells successfully wired up with the damaged spinal cord.
While the spinal cord was not repaired, the study did serve to improve the mice’s bladder control, while reducing pain — the former of which actually outranks walking as something many quadriplegics consider their highest priority for treatment, according to a 2004 study.
“Patients who suffer from spinal cord injury very often complain about neuropathic pain that is uncontrollable, as well as bowel and bladder incontinence,” Dr. Arnold Kriegstein, co-senior author of the study, told Digital Trends. “These are major complaints, in addition to issues like paralysis which most people are aware of following spinal cord injuries.”
Many of these complaints, Dr. Kriegstein said, are because the spinal cord circuits are more active than they should be.
“We therefore reasoned that if we could deliver focal inhibition to those circuits we may be able to restore a more normal balance of activity,” he said. “Our plan was to use inhibitory interneurons — which are neurons which normally form inhibitory connections with the cells around them — to graft them into the spinal cord in the area of those overactive circuits and suppress that activity. That was the rationale that made us try this approach.”
It is understandable that studies like this can cause excitement among readers and Dr. Kriegstein said that he fully appreciates the importance of this work.
“As a clinician, I’m very aware of the urgency that’s felt among patients who are often very desperate for treatment,” he said. “As a result, we’re very interested in accelerating this work toward clinical trials as soon as possible, but there are many steps along the way. We have to demonstrate that this is safe, as well as replicating it in other animals. This involves scaling up the production of these human interneurons in a way that would be compatible with a clinical product.”
In terms of a phase one clinical trial, the researchers are currently aiming for one to take place over the next three to four years. “That may seem a long timetable if you’re a follower of the tech industry, but when it comes to biotechnology and the pharmaceutical industry that’s rather fast,” Kriegstein said.