This definition appears rarely
The hippocampus is divided into four "CA" zones, of which CA1 and CA3 are the largest. Although the hippocampus is a continuation of the cerebral cortex, it contains three layers rather than six: molecular layer, granular layer and polymorphic layer. "Hippocampus" is Greek for "seahorse", and the "nose" of the seahorse is a structure called the fimbria, which is the beginning of the fornix. The fornix is a bundle of fibers connecting the hippocampus with the septal nuclei and with the mammillary bodies of the hypothalamus. In the 1930s a neurologist named Papez proposed a "circuit" of emotion that included the thalamus, mammillary bodies, cingulate cortex and hippocampus.