The retrosplenial cortex: A memory gateway between the cortical default mode network and the medial temporal lobe.
Neda Kaboodvand, Lars Bäckman, Lars Nyberg, Alireza Salami
Human Brain Mapping May 1, 2018 DOI: 10.1002/hbm.23983 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 180 |
| Population | Healthy old adults aged 64-68 years |
| Topics | Default mode network |
| Keywords | Aging Betweenness centrality Episodic memory Medial temporal lobe Multilevel meditation Retrosplenial cortex |
| Key findings | The retrosplenial cortex serves as a critical gateway between the medial temporal lobe and cortical default mode network regions, and its mediation is associated with better episodic memory performance in older adults. |
Abstract
The default mode network (DMN) involves interacting cortical areas, including the posterior cingulate cortex (PCC) and the retrosplenial cortex (RSC), and subcortical areas, including the medial temporal lobe (MTL). The degree of functional connectivity (FC) within the DMN, particularly between MTL and medial-parietal subsystems, relates to episodic memory (EM) processes. However, past resting-state studies investigating the link between posterior DMN-MTL FC and EM performance yielded inconsistent results, possibly reflecting heterogeneity in the degree of connectivity between MTL and specific cortical DMN regions. Animal work suggests that RSC has structural connections to both cortical DMN regions and MTL, and may thus serve as an intermediate layer that facilitates information transfer between cortical and subcortical DMNs. We studied 180 healthy old adults (aged 64-68 years), who underwent comprehensive assessment of EM, along with resting-state fMRI. We found greater FC between MTL and RSC than between MTL and the other cortical DMN regions (e.g., PCC), with the only significant association with EM observed for MTL-RSC FC. Mediational analysis showed that MTL-cortical DMN connectivity increased with RSC as a mediator. Further analysis using a graph-theoretical approach on DMN nodes revealed the highest betweenness centrality for RSC, confirming that a high proportion of short paths among DMN regions pass through RSC. Importantly, the degree of RSC mediation was associated with EM performance, suggesting that individuals with greater mediation have an EM advantage. These findings suggest that RSC forms a critical gateway between MTL and cortical DMN to support EM in older adults.
Comparable studies
Other observational and cohort studies on default mode network, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| A default mode of brain function Normal adult human brain | 2001 | Observational study | |
| Resting-State Functional Connectivity Reflects Structural Connectivity in the Default Mode Network Healthy subjects | 2008 | Observational cohort | |
| Meditation experience is associated with increased cortical thickness Participants with extensive Insight meditation experience and matched controls | 2005 | Observational cohort | n = 20 |
| Meditation experience is associated with differences in default mode network activity and connectivity Experienced meditators and matched meditation-naive controls | 2011 | Observational cohort | |
| The precuneus/posterior cingulate cortex plays a pivotal role in the default mode network: Evidence from a partial correlation network analysis Healthy subjects | 2008 | Observational study |
Citations in the library
Cited by 3
- Altered functional connectivity within the default mode network in two animal models with opposing episodic memories PLoS One September 18, 2018
- The Association Between Loss of Consciousness and the Default Mode Network at the Chronic Stage of Diffuse Axonal Injury: A Diffusion Tensor Imaging Study Journal of Clinical Medicine September 17, 2026
- Strengthened Hippocampal Circuits Underlie Enhanced Retrieval of Extinguished Fear Memories Following Mindfulness Training. Biological Psychiatry May 30, 2019
Cites 8
- A default mode of brain function Proceedings of the National Academy of Sciences January 16, 2001
- Resting-State Functional Connectivity Reflects Structural Connectivity in the Default Mode Network Cerebral Cortex April 9, 2008
- The precuneus/posterior cingulate cortex plays a pivotal role in the default mode network: Evidence from a partial correlation network analysis Neuroimage June 13, 2008
- Fractionating the Default Mode Network: Distinct Contributions of the Ventral and Dorsal Posterior Cingulate Cortex to Cognitive Control Journal of Neuroscience March 2, 2011
- Dynamic functional connectivity of the default mode network tracks daydreaming Neuroimage June 25, 2014
and 3 more in the library