Volume of the posterior hippocampus mediates age-related differences in spatial context memory and is correlated with increased activity in lateral frontal, parietal and occipital regions in healthy aging

NeuroImage

Can Fenerci¹  Sricharana Rajagopal²  Signy Sheldon³  Rosanna K. Olsen³  Kiera Hooper³  Camille Beaudoin⁴  M. Natasha Rajah⁴  Jamie Snytte⁴ 

[1] Brain Imaging Center, Douglas Institute Research Center, 6875 LaSalle Blvd Verdun, Montreal, QC H4H 1R3, Canada;Corresponding authors at: Brain Imaging Center, Douglas Institute Research Center, 6875 LaSalle Blvd Verdun, Montreal, QC H4H 1R3, Canada.;Brain Imaging Center, Douglas Institute Research Center, 6875 LaSalle Blvd Verdun, Montreal, QC H4H 1R3, Canada;Department of Psychology, McGill University, 2001 Avenue McGill College, Montreal, QC H3A 1G1, Canada;

关键词: Aging;    Medial temporal lobes;    Hippocampus;    Episodic memory;    Brain function;    Compensation;   

DOI  :  

来源: DOAJ

【 摘 要 】

Healthy aging is associated with episodic memory decline, particularly in the ability to encode and retrieve object-context associations (context memory). Neuropsychological and neuroimaging studies have highlighted the importance of the medial temporal lobes (MTL) in supporting episodic memory across the lifespan. However, given the functional heterogeneity of the MTL, volumetric declines in distinct regions may impact performance on specific episodic memory tasks, and affect the function of the large-scale neurocognitive networks supporting episodic memory encoding and retrieval. In the current study, we investigated how MTL structure may mediate age-related differences in performance on spatial and temporal context memory tasks, in a sample of 125 healthy adults aged 19–76 years old. Standard T1-weighted MRIs were segmented into the perirhinal, entorhinal and parahippocampal cortices, as well as the anterior and posterior hippocampal subregions. We observed negative linear and quadratic associations between age and volume of the parahippocampal cortex, and anterior and posterior hippocampal subregions. We also found that volume of the posterior hippocampus fully mediated the association between age and spatial, but not temporal context memory performance. Further, we employed a multivariate behavior partial-least-squares analysis to assess how age and regional MTL volumes correlated with brain activity during the encoding and retrieval of spatial context memories. We found that greater activity within lateral prefrontal, parietal, and occipital regions, as well as within the anterior MTL was related to older age and smaller volume of the posterior hippocampus. Our results highlight the heterogeneity of MTL contributions to episodic memory across the lifespan and provide support for the posterior-anterior shift in aging, and scaffolding theory of aging and cognition.

【 授权许可】

Unknown