Rats can use their brain activity to control an external device through an implanted electrode, even after a stroke. The finding suggests that people who have motor problems as a result of a stroke could one day benefit from such brain–machine interfaces.
Karunesh Ganguly at the San Francisco Veterans Affairs Medical Center in California and his colleagues placed electrodes near the part of the motor cortex in the rat brain that was injured by stroke, and then trained the animal to shift the angle of a water-feeding tube using just its brain activity. The team found that stroke-affected rats learned this task as quickly as control animals, even though the stroke animals showed only minimal improvements in movement.
The results suggest that the brain area injured by a stroke can still form new brain-cell connections.