The brain's memory center may come "prewired," rather than being built from scratch after birth, a new study in mice finds. The research, published in April in the journal Nature Communications , offers a new perspective on a long-standing question in neuroscience: Does the brain begin as a blank slate and build memories by adding connections through experience, or does it come with built-in wiring? The new research focused on the hippocampus , a seahorse-shaped structure deep in the brain that's essential for forming memories. The researchers focused on a region of the hippocampus called cornu ammonis 3 (CA3), which plays a central role in storing and recalling memories. A trait known as plasticity enables neurons within CA3 to continuously strengthen and weaken their connections and thus strengthen or weaken different memories. The team examined mouse brain tissue collected shortly after birth, during adolescence or during adulthood.…