The hippocampus is believed to be the brain’s primary learning and memory center and plays critical roles in processing, storing, and recalling information. This seahorse-shaped structure is highly susceptible to damage through stroke or lack of oxygen and is thought to be critically involved in Alzheimer’s disease. Life scientists from UCLA and Australia have now identified regions of the brain that are able to create alternate pathways to help compensate for the lost neural function. These complex new neural circuits are often far from the damaged hippocampus site. In rat-brain studies, parts of the prefrontal cortex were seen to take over when the hippocampus was disabled. Areas in the prefrontal cortex compensated in different ways, with one sub-region (infralimbic cortex) silencing its activity and another sub-region (prelimbic cortex) increasing its activity. This is the first demonstration of such neural-circuit plasticity and could potentially help scientists develop new treatments for Alzheimer’s disease, stroke, and other conditions involving damage to the brain.