scholarly journals Differences in functional connectivity along the anterior-posterior axis of human hippocampal subfields

2018 ◽  
Author(s):  
Marshall A. Dalton ◽  
Cornelia McCormick ◽  
Eleanor A. Maguire
Keyword(s):  
High Resolution ◽  
Functional Connectivity ◽  
Functional Mri ◽  
Resting State ◽  
Structural Mri ◽  
List Type ◽  
Hippocampal Subfields ◽  
Anterior Posterior ◽  
Anterior Posterior Axis ◽  
Synaptic Circuit

AbstractThere is a paucity of information about how human hippocampal subfields are functionally connected to each other and to neighbouring extra-hippocampal cortices. In particular, little is known about whether patterns of functional connectivity (FC) differ down the anterior-posterior axis of each subfield. Here, using high resolution structural MRI we delineated the hippocampal subfields in healthy young adults. This included the CA fields, separating DG/CA4 from CA3, separating the pre/parasubiculum from the subiculum, and also segmenting the uncus. We then used high resolution resting state functional MRI to interrogate FC. We first analysed the FC of each hippocampal subfield in its entirety, in terms of FC with other subfields and with the neighbouring regions, namely entorhinal, perirhinal, posterior parahippocampal and retrosplenial cortices. Next, we analysed FC for different portions of each hippocampal subfield along its anterior-posterior axis, in terms of FC between different parts of a subfield, FC with other subfield portions, and FC of each subfield portion with the neighbouring cortical regions of interest. We found that intrinsic functional connectivity between the subfields aligned generally with the tri-synaptic circuit but also extended beyond it. Our findings also revealed that patterns of functional connectivity between the subfields and neighbouring cortical areas differed markedly along the anterior-posterior axis of each hippocampal subfield. Overall, these results contribute to ongoing efforts to characterise human hippocampal subfield connectivity, with implications for understanding hippocampal function.HighlightsHigh resolution resting state functional MRI scans were collectedWe investigated functional connectivity (FC) of human hippocampal subfieldsWe specifically examined FC along the anterior-posterior axis of subfieldsFC between subfields extended beyond the canonical tri-synaptic circuitDifferent portions of subfields showed different patterns of FC with neocortex

Resting state functional connectivity of the hippocampus along the anterior–posterior axis and its association with glutamatergic metabolism

Cortex ◽  
2016 ◽  
Vol 81 ◽  
pp. 104-117 ◽  
Author(s):  
Gerd Wagner ◽  
Alexander Gussew ◽  
Stefanie Köhler ◽  
Feliberto de la Cruz ◽  
Stefan Smesny ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Resting State Functional Connectivity ◽  
Anterior Posterior ◽  
Anterior Posterior Axis

scholarly journals Impact of anaesthesia on static and dynamic functional connectivity in mice

2021 ◽  
Author(s):  
Tomokazu Tsurugizawa ◽  
Daisuke Yoshimaru
Keyword(s):  
Functional Connectivity ◽  
Functional Mri ◽  
Resting State ◽  
Low Frequency ◽  
Resting State Fmri ◽  
Brain Network ◽  
List Type ◽  
Thalamic Nuclei ◽  
Dynamic Functional Connectivity ◽  
Subcortical Regions

AbstractA few studies have compared the static functional connectivity between awake and anaesthetized states in rodents by resting-state fMRI. However, impact of anaesthesia on static and dynamic fluctuations in functional connectivity has not been fully understood. Here, we developed a resting-state fMRI protocol to perform awake and anaesthetized functional MRI in the same mice. Static functional connectivity showed a widespread decrease under anaesthesia, such as when under isoflurane or a mixture of isoflurane and medetomidine. Several interhemispheric connections were key connections for anaesthetized condition from awake. Dynamic functional connectivity demonstrates the shift from frequent broad connections across the cortex, the hypothalamus, and the auditory-visual cortex to frequent local connections within the cortex only. Fractional amplitude of low frequency fluctuation in the thalamic nuclei decreased under both anaesthesia. These results indicate that typical anaesthetics for functional MRI alters the spatiotemporal profile of the dynamic brain network in subcortical regions, including the thalamic nuclei and limbic system.HighlightsResting-state fMRI was compared between awake and anaesthetized in the same mice.Anaesthesia induced a widespread decrease of static functional connectivity.Anaesthesia strengthened local connections within the cortex.fALFF in the thalamus was decreased by anaesthesia.

scholarly journals Functional connectivity along the anterior–posterior axis of hippocampal subfields in the ageing human brain

Hippocampus ◽  
2019 ◽  
Vol 29 (11) ◽  
pp. 1049-1062 ◽  
Author(s):  
Marshall A. Dalton ◽  
Cornelia McCormick ◽  
Flavia De Luca ◽  
Ian A. Clark ◽  
Eleanor A. Maguire
Keyword(s):  
Functional Connectivity ◽  
Human Brain ◽  
Hippocampal Subfields ◽  
Anterior Posterior ◽  
Anterior Posterior Axis

scholarly journals Neuroimaging Anomalies in Community-Dwelling Asymptomatic Adults With Very Early-Stage White Matter Hyperintensity

2021 ◽  
Vol 13 ◽  
Author(s):  
Shuai Guan ◽  
Xiangyu Kong ◽  
Shifei Duan ◽  
Qingguo Ren ◽  
Zhaodi Huang ◽  
...  
Keyword(s):  
White Matter ◽  
Functional Mri ◽  
Resting State ◽  
Early Stage ◽  
Structural Mri ◽  
Resting State Fmri ◽  
Community Dwelling ◽  
White Matter Hyperintensity ◽  
Age Related ◽  
Comparative Results

White matter hyperintensity (WMH) is common in healthy adults in their 60s and can be seen as early as in their 30s and 40s. Alterations in the brain structural and functional profiles in adults with WMH have been repeatedly studied but with a focus on late-stage WMH. To date, structural and functional MRI profiles during the very early stage of WMH remain largely unexplored. To address this, we investigated multimodal MRI (structural, diffusion, and resting-state functional MRI) profiles of community-dwelling asymptomatic adults with very early-stage WMH relative to age-, sex-, and education-matched non-WMH controls. The comparative results showed significant age-related and age-independent changes in structural MRI-based morphometric measures and resting-state fMRI-based measures in a set of specific gray matter (GM) regions but no global white matter changes. The observed structural and functional anomalies in specific GM regions in community-dwelling asymptomatic adults with very early-stage WMH provide novel data regarding very early-stage WMH and enhance understanding of the pathogenesis of WMH.

scholarly journals Tonic resting-state hubness supports high-frequency activity defined verbal-memory encoding network in epilepsy

2019 ◽  
Author(s):  
Chaitanya Ganne ◽  
Walter Hinds ◽  
James Kragel ◽  
Xiaosong He ◽  
Noah Sideman ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Verbal Memory ◽  
Resting State ◽  
High Frequency ◽  
Cognitive Networks ◽  
Gamma Activity ◽  
List Type ◽  
Healthy Controls ◽  
Memory Encoding ◽  
Memory Network

AbstractHigh-frequency gamma activity of verbal-memory encoding using invasive-electroencephalogram coupled has laid the foundation for numerous studies testing the integrity of memory in diseased populations. Yet, the functional connectivity characteristics of networks subserving these HFA-memory linkages remains uncertain. By integrating this electrophysiological biomarker of memory encoding from IEEG with resting-state BOLD fluctuations, we estimated the segregation and hubness of HFA-memory regions in drug-resistant epilepsy patients and matched healthy controls. HFA-memory regions express distinctly different hubness compared to neighboring regions in health and in epilepsy, and this hubness was more relevant than segregation in predicting verbal memory encoding. The HFA-memory network comprised regions from both the cognitive control and primary processing networks, validating that effective verbal-memory encoding requires multiple functions, and is not dominated by a central cognitive core. Our results demonstrate a tonic intrinsic set of functional connectivity, which provides the necessary conditions for effective, phasic, task-dependent memory encoding.HighlightsHigh frequency memory activity in IEEG corresponds to specific BOLD changes in resting-state data.HFA-memory regions had lower hubness relative to control brain nodes in both epilepsy patients and healthy controls.HFA-memory network displayed hubness and participation (interaction) values distinct from other cognitive networks.HFA-memory network shared regional membership and interacted with other cognitive networks for successful memory encoding.HFA-memory network hubness predicted both concurrent task (phasic) and baseline (tonic) verbal-memory encoding success.

scholarly journals Simultaneous resting-state functional MRI and electroencephalography recordings of functional connectivity in patients with schizophrenia

2017 ◽  
Vol 71 (4) ◽  
pp. 262-270 ◽  
Author(s):  
Eiji Kirino ◽  
Shoji Tanaka ◽  
Mayuko Fukuta ◽  
Rie Inami ◽  
Heii Arai ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Functional Mri ◽  
Resting State

Hubs of Anticorrelation in High-Resolution Resting-State Functional Connectivity Network Architecture

2015 ◽  
Vol 5 (5) ◽  
pp. 267-275 ◽  
Author(s):  
Kaundinya Gopinath ◽  
Venkatagiri Krishnamurthy ◽  
Romeo Cabanban ◽  
Bruce A. Crosson
Keyword(s):  
High Resolution ◽  
Functional Connectivity ◽  
Resting State ◽  
Network Architecture ◽  
Resting State Functional Connectivity
Sign in / Sign up

Export Citation Format

Share Document