Laminar profile of hippocampal subregions during spatial navigation

Motivation: Despite substantial progress in understanding the role of the hippocampus in spatial navigation, the layer-specific microcircuits underlying distinct navigation processes are yet to be determined. Goal(s): We aimed to investigate the laminar organization of hippocampal subregions during spatial navigation including its relationship to specific strategies. Approach: Leveraging submillimeter-resolution fMRI at 7T, we quantified BOLD signal changes across hippocampal depths and applied mixed-effect models to probe the relationship between subregional laminar activity and specific strategies reflected by straight paths and deviation towards environmental boundaries. Results: We show that laminar profiles in hippocampal subregions are differentially associated with navigation strategies. Impact: Our results demonstrate the promise of laminar fMRI for mapping complex cognitive functions in the hippocampus at mesoscale. Given the vulnerability of this region to Alzheimer’s disease pathology, these findings may have clinical implications for early diagnosis.