title: Structural and functional connectivity of the precuneus and thalamus to the default mode network.
abstract: Neuroimaging studies have identified functional interactions between the thalamus, precuneus, and default mode network (DMN) in studies of consciousness. However, less is known about the structural connectivity of the precuneus and thalamus to regions within the DMN. We used diffusion tensor imaging (DTI) to parcellate the precuneus and thalamus based on their probabilistic white matter connectivity to each other and DMN regions of interest (ROIs) in 37 healthy subjects from the Human Connectome Database. We further assessed resting-state functional connectivity (RSFC) among the precuneus, thalamus, and DMN ROIs. The precuneus was found to have the greatest structural connectivity with the thalamus, where connection fractional anisotropy (FA) increased with age. The precuneus also showed significant structural connectivity to the hippocampus and middle pre-frontal cortex, but minimal connectivity to the angular gyrus and midcingulate cortex. In contrast, the precuneus exhibited significant RSFC with the thalamus and the strongest RSFC with the AG. Significant symmetrical structural connectivity was found between the thalamus and hippocampus, mPFC, sFG, and precuneus that followed known thalamocortical pathways, while thalamic RSFC was strongest with the precuneus and hippocampus. Overall, these findings reveal high levels of structural and functional connectivity linking the thalamus, precuneus, and DMN. Differences between structural and functional connectivity (such as between the precuneus and AG) may be interpreted to reflect dynamic shifts in RSFC for cortical hub-regions involved with consciousness, but could also reflect the limitations of DTI to detect superficial white matter tracts that connect cortico-cortical regions. Hum Brain Mapp 38:938-956, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: National Institutes of Health, NIAAA, Bethesda, Maryland.
authors.forename: Samantha I
authors.initials: SI
authors.lastname: Cunningham
authors.affiliation: National Institutes of Health, NIAAA, Bethesda, Maryland.
authors.forename: Dardo
authors.initials: D
authors.lastname: Tomasi
authors.affiliation: National Institutes of Health, NIAAA, Bethesda, Maryland.|National Institute of Health, NIDA, Bethesda, Maryland.
authors.forename: Nora D
authors.initials: ND
authors.lastname: Volkow
mesh_terms: D000328:Adult; D063132:Connectome; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D015999:Multivariate Analysis; D009413:Nerve Fibers, Myelinated; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000502:physiology*; D010296:Parietal Lobe / Q000000981:diagnostic imaging / Q000502:physiology*; D012146:Rest; D013788:Thalamus / Q000000981:diagnostic imaging / Q000502:physiology*; D055815:Young Adult
keywords: Human Connectome Project; default mode network; diffusion tensor imaging; precuneus; resting-state fMRI; thalamus