Hippocampus is a major component of human (and other mammals) brain. It is located in the medial temporal lobe of the brain, beneath the cortical surface. It is a three-layered paired structure with mirror-image halves. The name hippocampus comes from Greek and means sea horse, which is what it resembles in shape. Histologically hippocampus cortex, known as Ammon’s horn, can be divided into four sections CA1 to CA4, which have various sizes and amounts of nerve cells. CA1 region contains small pyramidal cells, the small CA2 region is made of small pyramidal cells, the CA3 field forms a broad, loose band of pyramidal neurons. Lastly, the CA4 region containing pyramidal cells that are surrounded by U-letter shaped dark seam of grey matter (dentate
