The primary mechanism of brain repair after stroke has been identified, according to findings published in Nature Neuroscience.
By examining brain tissue in mice, monkeys, and humans, S Thomas Carmichael, MD, PhD, from the David Geffen School of Medicine at the University of California Los Angeles and colleagues have pinpointed the molecule GDF10 (growth and differentiation factor 10) as a key repair mechanism after stroke.
When a blood vessel in the brain is blocked and a stroke occurs, nearby tissues are deprived of oxygen, which causes them to die. Repair mechanisms in the brain are then activated to try to overcome the damage. One of these mechanisms is axonal sprouting, which causes healthy neurons to send out new projections (sprouts) to re-establish damaged connections and form new ones, which results in partial recovery. The researchers found that axonal sprouting is triggered by GDF10.
“Stroke normally produces a limited pattern of axonal sprouting from motor or somatosensory cortex posteriorly to areas adjacent to or caudal to the stroke. GDF10 delivery induces a unique connectional pattern: substantial projections anterior from motor cortex to premotor and prefrontal areas,” wrote Songlin Li, PhD, from the David Geffen School of Medicine. “This anterior projection from motor cortex to premotor cortex is causally associated with functional recovery in this model of stroke.”
Previous studies suggested that GDF10 was involved in stroke repair, but its exact role was unclear. These new findings may help develop new strategies to promote recovery.