The brain displays a remarkable ability to adapt following injury by altering its connections through neural plasticity. However, we know very little about why plasticity occurs in some areas of the brain, and not others. Here we investigated how the monkey brain recovered following lesions to the hippocampus, a brain area critical to memory and spatial navigation. We discovered that we could accurately predict how brain areas would change their connections after the lesion by the pattern of connections and the types of cells in the area before the lesion. This gives us a key insight into why plasticity occurs where it does in the brain.