Researchers were able to regenerate “an astonishing degree” of damaged nerves in the spinal cords of rats, making breakthrough findings for stem cell sciences. In a recent study at the University of California, San Diego and VA San Diego Healthcare, scientists revealed that early stage neurons have the ability to survive and extend nerve tissues to form new, functional neuronal relays across an injury site in the adult central nervous system (CNS).
The findings could one day help scientists develop new treatments for severe spinal cord injuries, such herniated disc New Jersey, which is becoming increasingly common among aging patients.
The scientists embedded neural stem cells in a matrix of fibrin (a protein key to blood clotting that is already used in human neuron procedures), mixed with growth factors to form a gel. The gel was then applied to the injury site in rats with completely severed spinal cords.
In addition, adult cells above the injury site regenerated into the neural stem cells, establishing a new relay circuit that could be measured electrically. “By stimulating the spinal cord four segments above the injury and recording this electrical stimulation three segments below, we detected new relays across the transaction site,” the researchers said in their report.
The study also proved that at least some types of adult CNS axons can overcome a normally inhibitory growth environment to grow over long distances. Importantly, stem cells across species exhibit these properties. The work will be published in the journal Cell on September 14.
To confirm that the mechanism underlying recovery was due to formation of new relays, when rats recovered, their spinal cords were re-transected above the implant. The rats lost motor function – confirming formation of new relays across the injury.
The grafting procedure resulted in significant functional improvement: On a 21-point walking scale, without treatment, the rats score was only 1.5; following the stem cell therapy, it rose to 7 – a score reflecting the animals’ ability to move all joints of affected legs.
According to the researchers, the study makes clear that early-stage neurons can overcome inhibitors present in the adult nervous system that normally work to maintain the elaborate central nervous system and to keep cells in the adult CNS from growing aberrantly.