This image shows distinct neural connections in a cross section of a mouse's hippocampus, a region of the brain involved in remembering facts and events. The large crescent-shaped area in green is the CA1 hippocampal area. Its highly specialized neurons, called location cells, serve as the brain's GPS system for tracking location. In red, the CA2 hippocampal area. It is important for former memories of social interactions. The blue area shows the sites of transmission of nerve signals between neurons in the neighboring CA3 area and the dentate gyrus, part of the hippocampus involved in episodic memories.