title: Distinct hippocampal functional networks revealed by tractography-based parcellation.
abstract: Recent research suggests the anterior and posterior hippocampus form part of two distinct functional neural networks. Here we investigate the structural underpinnings of this functional connectivity difference using diffusion-weighted imaging-based parcellation. Using this technique, we substantiated that the hippocampus can be parcellated into distinct anterior and posterior segments. These structurally defined segments did indeed show different patterns of resting state functional connectivity, in that the anterior segment showed greater connectivity with temporal and orbitofrontal cortex, whereas the posterior segment was more highly connected to medial and lateral parietal cortex. Furthermore, we showed that the posterior hippocampal connectivity to memory processing regions, including the dorsolateral prefrontal cortex, parahippocampal, inferior temporal and fusiform gyri and the precuneus, predicted interindividual relational memory performance. These findings provide important support for the integration of structural and functional connectivity in understanding the brain networks underlying episodic memory.
authors.affiliation: Department of Psychology, York University, Toronto, ON, M3J 1P3, Canada. aadnan@yorku.ca.
authors.forename: Areeba
authors.initials: A
authors.lastname: Adnan
authors.affiliation: Krembil Neuroscience Center and Toronto Western Research Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.|Department of Psychology, University of Toronto, Toronto, ON, M5S 3G3, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Barnett
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, London, WC1E 6BT, UK.
authors.forename: Massieh
authors.initials: M
authors.lastname: Moayedi
authors.affiliation: Krembil Neuroscience Center and Toronto Western Research Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.|Centre for Developmental Cognitive Neuroscience, University College London, London, WC1E 3BG, UK.
authors.forename: Cornelia
authors.initials: C
authors.lastname: McCormick
authors.affiliation: Krembil Neuroscience Center and Toronto Western Research Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.|Department of Psychology, University of Toronto, Toronto, ON, M5S 3G3, Canada.
authors.forename: Melanie
authors.initials: M
authors.lastname: Cohn
authors.affiliation: Krembil Neuroscience Center and Toronto Western Research Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.|Department of Psychology, University of Toronto, Toronto, ON, M5S 3G3, Canada.
authors.forename: Mary Pat
authors.initials: MP
authors.lastname: McAndrews
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology; D001931:Brain Mapping / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006624:Hippocampus / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D010296:Parietal Lobe / Q000033:anatomy & histology / Q000502:physiology; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000502:physiology; D013702:Temporal Lobe / Q000033:anatomy & histology / Q000502:physiology
keywords: DTI; Hippocampus; Networks; Recognition memory; fMRI