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Uncovering a role for the dorsal hippocampal commissure in recognition memory
Postans, Mark Parker, Greg D. Lundell, Henrik Ptito, M. Hamandi, K. Gray, W. P. Aggleton, John P. Dyrby, Tim B. Jones, Derek K. Winter, Michelle
Postans, Mark
Parker, Greg D.
Lundell, Henrik
Ptito, M.
Hamandi, K.
Gray, W. P.
Aggleton, John P.
Dyrby, Tim B.
Jones, Derek K.
Winter, Michelle
Abstract
The dorsal hippocampal commissure (DHC) is a white matter tract that provides interhemispheric connections between temporal lobe brain regions. Despite the importance of these regions for learning and memory, there is scant evidence of a role for the DHC in successful memory performance. We used diffusion-weighted magnetic resonance imaging (DW-MRI) and white matter tractography to reconstruct the DHC in both humans (in vivo) and nonhuman primates (ex vivo). Across species, our findings demonstrate a close consistency between the known anatomy and tract reconstructions of the DHC. Anterograde tract-tracer techniques also highlighted the parahippocampal origins of DHC fibers in nonhuman primates. Finally, we derived diffusion tensor MRI metrics from the DHC in a large sample of human subjects to investigate whether interindividual variation in DHC microstructure is predictive of memory performance. The mean diffusivity of the DHC correlated with performance in a standardized recognition memory task, an effect that was not reproduced in a comparison commissure tract—the anterior commissure. These findings highlight a potential role for the DHC in recognition memory, and our tract reconstruction approach has the potential to generate further novel insights into the role of this previously understudied white matter tract in both health and disease.
Keywords
familiarity, hippocampal commissure, recognition memory, recollection, tractography
Date
2020
Type
Journal article
Journal
Cerebral Cortex
Book
Volume
30
Issue
3
Page Range
1001-1015
Article Number
ACU Department
Collections
Relation URI
Source URL
Event URL
Open Access Status
Open access
License
CC BY 4.0
File Access
Open