Age-related hippocampal resting-state connectivity shows axis-dependent associations with memory

• Functional connectivity across large-scale brain networks alters in older age and changes are often associated with memory decline. Studies assessing hippocampal resting-state functional connectivity (rsFC), however, rarely consider the anterior and posterior hippocampus separately, although evidence suggests they are part of two distinct networks differentially supporting memory. While only a limited number of studies have considered age effects on axis-related hippocampal connectivity, findings suggest that rsFC of the two regions display differential effects of age. Reports on the link between such effects and memory are however inconclusive, and previous findings mainly concern episodic memory, ignoring spatial memory also dependent on the hippocampus. Here, we therefore assessed age effects on axis-related hippocampal rsFC, accounting for associations with both episodic and spatial memory in young, middle-aged and older adults (n=194). The anterior and posterior hippocampus showed different age-related decreases in connectivity assessed across middle and older age, but common to the regions was a decreased coupling with the medial orbitofrontal cortex. Only connectivity between the posterior hippocampus and the lingual gyrus increased as a function of age, displaying negative associations with episodic memory. In contrast, the region’s connectivity with the insula, decreasing with age, was positively related to spatial memory. Consistent with previous reports, our findings indicate that hippocampal rsFC vary with age in an axis-dependent manner, and further add to the knowledge on this differentiation’s relevance to memory by showing that age-related rsFC of the anterior and posterior hippocampus is differentially associated with episodic and spatial memory.

Subject headings

SAMHÄLLSVETENSKAP  -- Psykologi (hsv//swe)

SOCIAL SCIENCES  -- Psychology (hsv//eng)

Keyword

Aging

Episodic Memory

Hippocampus

Longitudinal axis

Sex

Spatial Memory

Publication and Content Type

vet (subject category)

ovr (subject category)