Entorhinal cortex

The entorhinal cortex (plural: cortices) (a.k.a. Brodmann area 28) is located in the mesial temporal lobe and acts as the interface between the hippocampus and the neocortex. It has been considered part of the hippocampal formation (along with Ammon’s horn, subiculum and presubiculum), but is difficult to precisely localize anatomically, with numerous definitions described . It occupies the middle portion of the medial temporal region, and includes part of the parahippocampal gyrus and gyrus ambiens .  However, increasingly it is defined by its connectivity to the hippocampus .

Having said that the following anatomical boundaries exist, if somewhat ill-defined :

• anterior relation: rhinal sulcus, separating it from the olfactory cortex
• dorsomedial relation: merges with the rest of the hippocampal formation, below the pes hippocampi and the amygdala; posteriorly it abuts the pre- and para-subiculum. 
• lateral relation: collateral sulcus
• posterior (caudal) relation: blends with the more posterior parts of parahippocampal cortex

Fiber density between the rhinal cortex and activated ventrolateral prefrontal regions has been shown to predict episodic memory performance .