Anatomical and microstructural determinants of hippocampal subfield functional connectome embedding

Wael, Reinder Vos de; Larivière, Sara; Caldairou, Benoît; Hong, Seok‐Jun; Margulies, Daniel S.; Jefferies, Elizabeth; Bernasconi, Andrea; Smallwood, Jonathan; Bernhardt, Boris C.

doi:10.1073/pnas.1803667115

Cited by 214 publications

(314 citation statements)

References 55 publications

Supporting

Mentioning

264

Contrasting

Order By: Relevance

“…Prior work has shown that neocortical connectivity variations follow a gradient running from unimodal toward transmodal regions while hippocampal connectivity gradually shifts along its longaxis Margulies et al, 2016;Plachti et al, 2019;Vos de Wael et al, 2018). Specifically, we remapped cortical and hippocampal morphometric and Aβ measures according to the main axes of neocortical and hippocampal connectivity.…”

Section: Discussionmentioning

confidence: 99%

“…Recent application of unsupervised compression techniques applied to cortico-cortical functional connectivity data recapitulated a similar gradient in humans (Margulies et al, 2016). In the hippocampus, this gradient follows its "long-axis," with anterior segments being closely connected to transmodal DMN and temporo-limbic networks, while posterior sections increasingly interact with posterior cortical areas including the visual and dorsal/ventral attention networks (Vos de Wael et al, 2018). Equivalent compression techniques have been applied to hippocampus-to-cortex connectivity profiles, also revealing a principal gradient of connectivity.…”

Section: Introductionmentioning

confidence: 90%

“…Significant negative correlations between age and F1 and F2 scores are also displayed. (b) Vertex-wise age effects on hippocampal subregional volume and Aβ deposition (left), mapped to a "long-axis" reference space based on hippocampal functional connectivity gradients (center, adapted from Vos de Wael et al, 2018), showing more elevated deposition in anterior subregions. (c) Correlation analysis between hippocampal volume and amyloid deposition with F1 and F2.…”

Section: Additional Control Analysesmentioning

confidence: 99%

See 2 more Smart Citations

Targeting age‐related differences in brain and cognition with multimodal imaging and connectome topography profiling

Lowe

Paquola

Wael

et al. 2019

Human Brain Mapping

Self Cite

View full text Add to dashboard Cite

Aging is characterized by accumulation of structural and metabolic changes in the brain. Recent studies suggest transmodal brain networks are especially sensitive to aging, which, we hypothesize, may be due to their apical position in the cortical hierarchy. Studying an open-access healthy cohort (n = 102, age range = 30-89 years) with MRI and Aβ PET data, we estimated age-related cortical thinning, hippocampal atrophy and Aβ deposition. In addition to carrying out surface-based morphological and metabolic mapping experiments, we stratified effects along neocortical and hippocampal resting-state functional connectome gradients derived from independent datasets. The cortical gradient depicts an axis of functional differentiation from sensory-motor regions to transmodal regions, whereas the hippocampal gradient recapitulates its long-axis. While age-related thinning and increased Aβ deposition occurred across the entire cortical topography, increased Aβ deposition was especially pronounced toward higher-order transmodal regions. Age-related atrophy was greater toward the posterior end of the hippocampal long-axis. No significant effect of age on Aβ deposition in the hippocampus was observed. Imaging markers correlated with behavioral measures of fluid intelligence and episodic memory in a topography-specific manner, confirmed using both univariate as well as multivariate analyses. Our results strengthen existing evidence of structural and metabolic change in the aging brain and support the use of connectivity gradients as a compact framework to analyze and conceptualize brain-based biomarkers of aging.aging, amyloid, atrophy, cognition, hippocampus, neocortex Alexander J. Lowe and Casey Paquola authors are contributed equally to this work.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 90%

Section: Additional Control Analysesmentioning

confidence: 99%

See 1 more Smart Citation

Targeting age‐related differences in brain and cognition with multimodal imaging and connectome topography profiling

Lowe

Paquola

Wael

et al. 2019

Human Brain Mapping

Self Cite

View full text Add to dashboard Cite

show abstract

“…Connectivity reductions, sometimes together with scattered increases, have also been reported between mesiotemporal regions and nodes of the default mode network (DMN), notably prefrontal and midline parietal cortices . In healthy populations, hippocampal and parahippocampal cortices interact closely with the DMN and form an important subcomponent that is relevant for memory . Of interest, the severity of hippocampal structural pathology in TLE relates directly to reductions in its functional connectivity, with patients who display marked sclerosis generally showing lower connectivity to DMN hubs than those with isolated gliosis (Figure , bottom left ) .…”

Section: Toward a Network‐level Conceptualization Of Focal Epilepsymentioning

confidence: 94%

“…Given T2‐weighted MRI sensitivity to reactive astrogliosis (sometimes the only detectable pathology in patients with subtle neuronal loss), T2‐weighted MRI and T2 relaxometry offer complementary information for MTS detection . Furthermore, increased access to high‐field scanners provides contrast‐rich data with submillimetric resolution in feasible acquisition times, sufficient to resolve hippocampal subfields and their internal structure . In TLE, subfield assessments have shown improved detection of subtle MTS and combinations of subfield imaging and surface‐shape modeling can increase analysis resolution, allowing continuous parameter analyses along the long axis.…”

Section: Imaging the Lesion Spectrummentioning

confidence: 99%

Neuroimaging and connectomics of drug‐resistant epilepsy at multiple scales: From focal lesions to macroscale networks

et al. 2019

Self Cite

View full text Add to dashboard Cite

Summary Epilepsy is among the most common chronic neurologic disorders, with 30%‐40% of patients having seizures despite antiepileptic drug treatment. The advent of brain imaging and network analyses has greatly improved the understanding of this condition. In particular, developments in magnetic resonance imaging (MRI) have provided measures for the noninvasive characterization and detection of lesions causing epilepsy. MRI techniques can probe structural and functional connectivity, and network analyses have shaped our understanding of whole‐brain anomalies associated with focal epilepsies. This review considers the progress made by neuroimaging and connectomics in the study of drug‐resistant epilepsies due to focal substrates, particularly temporal lobe epilepsy related to mesiotemporal sclerosis and extratemporal lobe epilepsies associated with malformations of cortical development. In these disorders, there is evidence of widespread disturbances of structural and functional connectivity that may contribute to the clinical and cognitive prognosis of individual patients. It is hoped that studying the interplay between macroscale network anomalies and lesional profiles will improve our understanding of focal epilepsies and assist treatment choices.

show abstract

Hubs disruption in mesial temporal lobe epilepsy. A resting‐state fMRI study on a language‐and‐memory network

Roger

Pichat

Torlay

et al. 2019

Human Brain Mapping

View full text Add to dashboard Cite

Mesial temporal lobe epilepsy (mTLE) affects the brain networks at several levels and patients suffering from mTLE experience cognitive impairment for language and memory. Considering the importance of language and memory reorganization in this condition, the present study explores changes of the embedded languageand-memory network (LMN) in terms of functional connectivity (FC) at rest, as measured with functional MRI. We also evaluate the cognitive efficiency of the reorganization, that is, whether or not the reorganizations support or allow the maintenance of optimal cognitive functioning despite the seizure-related damage.Data from 37 patients presenting unifocal mTLE were analyzed and compared to 48 healthy volunteers in terms of LMN-FC using two methods: pairwise correlations (region of interest [ROI]-to-ROI) and graph theory. The cognitive efficiency of the LMN-FC reorganization was measured using correlations between FC parameters and language and memory scores. Our findings revealed a large perturbation of the LMN hubs in patients. We observed a hyperconnectivity of limbic areas near the dysfunctional hippocampus and mainly a hypoconnectivity for several cortical regions remote from the dysfunctional hippocampus. The loss of FC was more important in left mTLE (L-mTLE) than in right (R-mTLE) patients. The LMN-FC reorganization may not be always compensatory and not always useful for patients as it may be associated with lower cognitive performance. We discuss the different connectivity patterns obtained and conclude that interpretation of FC changes in relation to neuropsychological scores is important to determine cognitive efficiency, suggesting the concept of "connectome" would gain to be associated with a "cognitome" concept. K E Y W O R D S brain plasticity, functional connectivity, graph theory, language, memory, mesial temporal lobe epilepsy, resting-state fMRI

show abstract

Anatomical and microstructural determinants of hippocampal subfield functional connectome embedding

Cited by 214 publications

References 55 publications

Targeting age‐related differences in brain and cognition with multimodal imaging and connectome topography profiling

Targeting age‐related differences in brain and cognition with multimodal imaging and connectome topography profiling

Neuroimaging and connectomics of drug‐resistant epilepsy at multiple scales: From focal lesions to macroscale networks

Hubs disruption in mesial temporal lobe epilepsy. A resting‐state fMRI study on a language‐and‐memory network

Contact Info

Product

Resources

About