Brain Rewires Itself after Damage or Injury

When the brain's primary "learning center" is damaged, complex new neural circuits arise to compensate for the lost function, say life scientists from UCLA and Australia who have pinpointed the regions of the brain involved in creating those alternate pathways — often far from the damaged site. The research, conducted by UCLA's Dr. Michael Fanselow and Moriel Zelikowsky in collaboration with Dr. Bryce Vissel, a group leader of the neuroscience research program at Sydney's Garvan Institute of Medical Research, was published online on May 15, 2013 in PNAS. The researchers found that parts of the prefrontal cortex take over when the hippocampus, the brain's key center of learning and memory formation, is disabled. Their breakthrough discovery, the first demonstration of such neural-circuit plasticity, could potentially help scientists develop new treatments for Alzheimer's disease, stroke, and other conditions involving damage to the brain. For the study, Dr. Fanselow and Ms. Zelikowsky conducted laboratory experiments with rats showing that the rodents were able to learn new tasks even after damage to the hippocampus. While the rats needed more training than they would have normally, they nonetheless learned from their experiences — a surprising finding. "I expect that the brain probably has to be trained through experience," said Dr. Fanselow, a professor of psychology and member of the UCLA Brain Research Institute, who was the study's senior author. "In this case, we gave animals a problem to solve." After discovering the rats could, in fact, learn to solve problems, Zelikowsky, a graduate student in Fanselow's laboratory, traveled to Australia, where she worked with Dr. Vissel to analyze the anatomy of the changes that had taken place in the rats' brains.