ABSTRACT
The hippocampus is situated within the hippocampal fissure, close to the parahippocampal gyrus, part of the temporal lobes on both sides (see Chapter 1 and Figures 1.4, 9.1, 10.3, 10.4 and 10.5) (Blows 2000). This area is sometimes called the hippocampal complex or hippocampal formation, because several structures occur close together and have many interconnections with each other. The components of the complex are:
• the dentate gyrus, the innermost cell layer of the hippocampus; • Ammon’s horn (see Figure 10.3, Chapter 10), another part of the hippocampus, consisting
also of a layer of neurons that can be subdivided into four areas, CA1, CA2, CA3, and CA4 (where CA means cornu Ammonis, or ‘Ammon’s horn’);
• the subiculum, also included in the hippocampus by some authors; • the entorhinal cortex, which lies between the subiculum and the perirhinal cortex
(see Figure 10.3); • the perirhinal cortex, which lies between the entorhinal cortex and the parahippocampal
cortex (Figure 10.3); • the parahippocampal cortex, the outermost component of the complex (see
Figures 9.1, 10.3).
