The retrosplenial cortex: A memory gateway between the cortical default mode network and the medial temporal lobe.
Human Brain Mapping May 1, 2018 Neda Kaboodvand, Lars Bäckman, Lars Nyberg et al.
The retrosplenial cortex (RSC) acts as a critical gateway between the medial temporal lobe (MTL) and other cortical regions of the default mode network (DMN), supporting episodic memory in older adults. In 180 healthy adults aged 64-68, functional connectivity between MTL and RSC was stronger than between MTL and other DMN regions like the posterior cingulate cortex, and only MTL-RSC connectivity was significantly associated with episodic memory performance. Mediation analysis showed that MTL-cortical DMN connectivity increased with RSC as a mediator, and graph-theoretical analysis revealed the highest betweenness centrality for RSC. The degree of RSC mediation was associated with better episodic memory, indicating that individuals with greater mediation have a memory advantage.