The term hippocampal formation refers to a functionally defined composite structure of the limbic lobe defined on the basis of internal structure, connectivity, and role in the recording, storage and retrieval of declarative memory. In the primate, it includes the hippocampal complex, the presubiculum, parasubiculum and entorhinal cortex of the anterior parahippocampal gyrus ( Insausti-2012 ). The rat ( Swanson-2004 ) and the mouse ( Franklin-2008 ) have an equivalent combination of structures except that it includes a postsubiculum and it is located ventrally on the mesial surface at the caudal pole of the cerebral hemisphere ( Squire-2004 ). The histological components in the rat ( Swanson-2004 ) and the mouse ( Hof-2000 ).are the same as in primates except that in those species it also includes the fasciola cinerea and and indusium griseum. In the noninvasive imaging literature, the hippocampal formation, which is located in the limbic lobe, is commonly referred to by the misnomer 'medial temporal lobe'. (updated 18 May 2024).