Temporolimbic cortical volume is associated with semantic odor memory performance in aging

Area of Science:

• Neuroscience
• Gerontology
• Cognitive Science

Background:

• Olfactory function, particularly odor identification, is increasingly recognized as a predictor of cognitive function in aging.
• This association suggests olfactory capacity may reflect the health of temporolimbic cortical networks, but specific structural links require further elucidation.

Purpose of the Study:

• To investigate the association between gray matter volumes in olfactory and memory regions and semantic olfactory memory performance in an aging population.
• To explore potential overlap and differences in structural correlates between semantic and episodic olfactory memory.

Main Methods:

• Voxel-based morphometry was used in a region of interest-based analysis.
• Structural MRI data were collected from 422 participants (aged ≥60 years) from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K).
• Semantic and episodic odor memory, alongside verbal memory, were assessed.

Main Results:

• Semantic olfactory memory showed a positive association with gray matter volume in a region encompassing the anterior hippocampus, amygdala, and posterior piriform cortex.
• This association remained significant even after controlling for verbal memory performance.
• Episodic olfactory memory did not show a similar significant association with gray matter volume.

Conclusions:

• The findings provide evidence for distinct functional-structural associations related to semantic odor memory.
• This supports the hypothesis that temporolimbic network integrity is a neurobiological substrate linking olfactory function to cognitive health in older age.