New evidence from a patient shows that the area of the brain that processes visual inputs can reorganize after an injury caused by stroke.
Scientists found that a brain region that had stopped receiving signals from the eyes because of a stroke began responding to signals formerly processed in adjacent brain areas.
This finding demonstrates plasticity, the ability of a brain area to change its functioning, in the adult human brain. The finding will not lead immediately to treatments, but may eventually play a role in designing new therapies to aid recovery following stroke and brain injury, say the authors, whose study appears in the September 5 issue of The Journal of Neuroscience.
“The results shed light on the ability of the adult human brain to reorganize itself and on the functional consequences of such reorganization,” says Shimon Ullman, PhD, of the Weizmann Institute of Science in Israel. “Considerable plasticity of the brain has been demonstrated in various animals and different brain regions, but relatively little has been known about such reorganization processes of the human visual system.” Ullman was not involved in the study.
Daniel Dilks, PhD, of Massachusetts Institute of Technology, and colleagues studied a 51-year-old man six months after he suffered a stroke. It damaged nerve fibers that transmitted information from his eye to one region of his visual cortex, which processes visual inputs, rendering him partially blind. The cortex itself was not injured.