"Permanent" injuries may have a cure.

Novel methods for transplanting cells into areas damaged by spinal cord injury and experimental drug treatments show promise for aiding those suffering from devastating injuries. "New animal research brings increasing hope for sufferers of spinal cord injury," notes Oswald Steward, of the Reeve-Irvine Research Center at the University of California College of Medicine, Irvine. "Studies are beginning to invalidate one of the longer held 'truths' in medicine--that nerve cells of the spinal cord are not able to re-grow once damaged."

Research demonstrates that a special type of cell transplanted into injured rat spinal cords forms myelin-the insulating material around nerves that speeds conduction of nerve impulses--and improves rats' functioning, according to scientists in the department of neurology at Yale University School of Medicine, New Haven, Conn.

Olfactory ensheathing cells (OECs) are specialized glial cells found in nerves and brain tissue associated with the sense of smell. Nerve cells within the olfactory tissue in the nose divide throughout life and send new axons--or nerve fibers--to transmit smell sensations to the brain. Scientists have long thought that OECs assist the normal regeneration of these axons and guide them into the brain where they make new functional connections. Because axons lose myelin after a trauma such as spinal cord injury, scientists have explored using OECs as a possible treatment.

The Yale researchers obtained OECs from the olfactory bulbs of adult transgenic--genetically altered-rats expressing green fluorescent protein and transplanted them into other rats' spinal cords that had been cut completely at the dorsal funicular location. The green fluorescent protein allowed the cells to be viewed easily in the spinal cord. The researchers observed groups of regenerating nerve fibers crossing the spinal cord injury site and the alignment of green cells forming myelin. Electron microscopic examination of the tissue showed that myelin was indeed produced around the axons by the transplanted cells.

"These results indicate that a number of factors including remyelination of axons may contribute to improvement in function following transplantation of OECs into the injured spinal cord," says Yale neurologist Masanori Sasaki.