RT Journal Article SR Electronic T1 Postnatal development of projections of the postrhinal cortex to the entorhinal cortex in the rat JF eneuro JO eNeuro FD Society for Neuroscience SP ENEURO.0057-22.2022 DO 10.1523/ENEURO.0057-22.2022 A1 Maria Jose Lagartos-Donate A1 Thanh Pierre Doan A1 Paulo J. B. Girão A1 Menno P. Witter YR 2022 UL http://www.eneuro.org/content/early/2022/06/17/ENEURO.0057-22.2022.abstract AB The ability to encode and retrieve contextual information is an inherent feature of episodic memory that starts to develop during childhood. The postrhinal cortex, an area of the parahippocampal region, has a crucial role in encoding object-space information and translating egocentric to allocentric representation of local space. The strong connectivity of POR with the adjacent entorhinal cortex, and consequently the hippocampus, suggests that the development of these connections could support the postnatal development of contextual memory. Here, we report that postrhinal cortex projections of the rat develop progressively from the first to the third postnatal week starting in the medial entorhinal cortex before spreading to the lateral entorhinal cortex. The increased spread and complexity of postrhinal axonal distributions is accompanied by an increased complexity of entorhinal dendritic trees and an increase of postrhinal – entorhinal synapses, which supports a gradual maturation in functional activity.SIGNIFICANCE STATEMENTPostrhinal-entorhinal cortical interplay mediates important aspects of encoding and retrieval of contextual information that is important for episodic memory. To better understand the function of the postrhinal interactions with the entorhinal cortex we studied the postnatal development of the connection between the two cortical areas. Our study describes the postnatal development of the postrhinal-to-entorhinal projections as established with neuroanatomical and electrophysiological methods. The projections gradually reach functionally different areas of the entorhinal cortex, reaching the area involved in spatial functions first, followed by the part involved in representing information about objects and sequences of events.