In tests on stroke-damaged rats Kartje and her research team used a very specific antibody, an immune-system protein, to stop Nogo-A from binding to receptors on nerve cells. Without the inhibitory affect of Nogo-A, the injured nerve cells were able to re-grow, restoring lost movement to the front paws of the rats. “For the first time really we know that there is hope for people who have been disabled from stroke,” says Kartje.
As she reported in the Journal of Cerebral Blood Flow & Metabolism, they initially trained aging rats — the equivalent of 70 or 80 years old in human terms — to perform highly skilled tasks, such as reaching through a small hole for food and walking along the rungs of a ladder, which required precise forelimb movement and coordination. A stroke was surgically induced in either the left or the right side of the sensory-motor cortex — the area at the top of the brain that controls conscious body movement — left the rats with paralysis of the paws on one side, and unable to do the tasks.
A week after the stroke, the rats began the two-week antibody treatment to block Nogo-A. “We’re giving it one week after the stroke, which gives us a lot of time in the clinical world to get things organized and set up and to actually get therapy to the patient,” Kartje explains. Just nine weeks after the treatment the aged rats recovered the use of their paralyzed paws. “Basically they begin to dramatically improve,” she says. “And we’ve looked at the connections in the brain, and it’s because of reorganization. So, new brain connections are actually formed.”
