Communication between subregions of the parahippocampal region

The functional interactions between PHR regions derived by the analysis of the physiological data reveal a peculiar organization that does not emerge from the evaluation of the neuroanatomical studies. Tracer studies demonstrate the existence of strong intrinsic fibre systems along longitudinal cortical bands within the ERC and the PRC. The electrophysiological findings herewith reviewed confirm that longitudinal fibre pathways sustain an efficient propagation of excitation that link distant cortical portions within each PHR subregion, that is, area 36, area 35, lateral ERC, and medial ERC.