Hippocampus brain tissue Light micrograph of a sagittal side view section through the hippocampus of a rats brain showing the nerve cells within it The hippocampus is a structure of the limbic system of the brain There is a hippocampus in each cerebral hemisphere and they are thought to be responsible for spatial awareness and the formation of memories Different structures have been stained different colours the nuclei of cells are orange and neurofilaments are blue Neurofilaments are proteins found in the axons output processes of nerve cells