Research indicates that improvement of chronic neurologic defi cits and enhancement of neuronal plasticity can be induced in adult rats with anti-Nogo-A immunotherapy.
An experimental treatment that jumpstarts the growth of nerve fibers could reverse much of the damage caused by strokes, researchers reported in the November 18, 2010, online issue of Stroke.
“This therapy may be used to restore function even when it’s given long after ischemic brain damage has occurred,” wrote senior author Gwendolyn Kartje, MD, PhD, and colleagues. Dr. Kartje is Director of the Neuroscience Institute of Loyola University Chicago Stritch School of Medicine and Chief of Neuroscience Research at Edward Hines Jr. VA Hospital in Hines, Illinois.
Dr. Kartje and colleagues reported their results with anti-Nogo-A immunotherapy, which has previously been shown to improve function and enhance plasticity after acute ischemic stroke in adult rats. In the present study, the researchers sought to determine whether similar benefits could be induced by anti-Nogo-A immunotherapy in chronic stroke-impaired rats.
The researchers trained rats to reach and grab food pellets with their front paws. The preferred forelimb was then impaired with a permanent middle cerebral artery occlusion. Nine weeks later animals showing a profound deficit were randomly distributed to three groups. Six rats received anti-Nogo-A therapy, four rats received a control treatment consisting of an inactive antibody, and five rats received no treatment. Animals treated with anti-Nogo-A immunotherapy began to show improvement three weeks after treatment.
The rats that had received anti-Nogo-A therapy regained 78% of their pre-stroke ability to grab pellets. By comparison, the rats who received no treatment regained 47% of their pre-stroke ability, and rats receiving the control treatment of inactive antibodies regained 33% of their pre-stroke performance.
Subsequent examination of brain tissue using biotin dextran amine-labeled axonal fiber analysis showed that anti-Nogo-treated rats experienced significant sprouting of axons.
Researchers wrote that anti-Nogo-A therapy “can induce remarkable compensatory sprouting and fiber growth, indicating the responsiveness of the chronically injured brain to form new neural networks under the proper growth conditions.”
The findings “are of great clinical importance,” researchers concluded. Anti-Nogo-A therapy “may benefit not only victims of spinal cord injury or patients in the early stage of stroke recovery, but also patients in later stages who suffer from neurological disability due to brain damage from stroke or other causes.”