A systematic review on the quantitative relationship between structural and functional network connectivity strength in mammalian brains

The mammalian brain is composed of densely connected and interacting regions, which form structural and functional networks. An improved understanding of the structure–function relation is crucial to understand the structural underpinnings of brain function and brain plasticity after injury. It is currently unclear how functional connectivity strength relates to structural connectivity strength. We obtained an overview of recent papers that report on correspondences between quantitative functional and structural connectivity measures in the mammalian brain. We included network studies in which functional connectivity was measured with resting-state fMRI, and structural connectivity with either diffusion-weighted MRI or neuronal tract tracers. Twenty-seven of the 28 included studies showed a positive structure–function relationship. Large inter-study variations were found comparing functional connectivity strength with either quantitative diffusion-based (correlation coefficient (r) ranges: 0.18–0.82) or neuronal tracer-based structural connectivity measures (r = 0.24–0.74). Two functional datasets demonstrated lower structure–function correlations with neuronal tracer-based (r = 0.22 and r = 0.30) than with diffusion-based measures (r = 0.49 and r = 0.65). The robust positive quantitative structure–function relationship supports the hypothesis that structural connectivity provides the hardware from which functional connectivity emerges. However, methodological differences between the included studies complicate the comparison across studies, which emphasize the need for validation and standardization in brain structure–function studies.

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Distinct structure-function relationships across cortical regions and connectivity scales in the rat brain

10.1101/742833 ◽

2019 ◽

Author(s):

Milou Straathof ◽

Michel R.T. Sinke ◽

Theresia J.M. Roelofs ◽

Erwin L.A. Blezer ◽

R. Angela Sarabdjitsingh ◽

...

Keyword(s):

Functional Connectivity ◽

Structure Function ◽

Rat Brain ◽

Resting State ◽

Structural Connectivity ◽

Distinct Structure ◽

Macro Scale ◽

Function Relationship ◽

The Brain ◽

Meso Scale

AbstractAn improved understanding of the structure-function relationship in the brain is necessary to know to what degree structural connectivity underpins abnormal functional connectivity seen in many disorders. We integrated high-field resting-state fMRI-based functional connectivity with high-resolution macro-scale diffusion-based and meso-scale neuronal tracer-based structural connectivity, to obtain an accurate depiction of the structure-function relationship in the rat brain. Our main goal was to identify to what extent structural and functional connectivity strengths are correlated, macro- and meso-scopically, across the cortex. Correlation analyses revealed a positive correspondence between functional connectivity and macro-scale diffusion-based structural connectivity, but no correspondence between functional connectivity and meso-scale neuronal tracer-based structural connectivity. Locally, strong functional connectivity was found in two well-known resting-state networks: the sensorimotor and default mode network. Strong functional connectivity within these networks coincided with strong short-range intrahemispheric structural connectivity, but with weak heterotopic interhemispheric and long-range intrahemispheric structural connectivity. Our study indicates the importance of combining measures of connectivity at distinct hierarchical levels to accurately determine connectivity across networks in the healthy and diseased brain. Distinct structure-function relationships across the brain can explain the organization of networks and may underlie variations in the impact of structural damage on functional networks and behavior.

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Distinct structure-function relationships across cortical regions and connectivity scales in the rat brain

Scientific Reports ◽

10.1038/s41598-019-56834-9 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Milou Straathof ◽

Michel R. T. Sinke ◽

Theresia J. M. Roelofs ◽

Erwin L. A. Blezer ◽

R. Angela Sarabdjitsingh ◽

...

Keyword(s):

Functional Connectivity ◽

Structure Function ◽

Rat Brain ◽

Resting State ◽

Structural Connectivity ◽

Distinct Structure ◽

Macro Scale ◽

Function Relationship ◽

The Brain ◽

Meso Scale

AbstractAn improved understanding of the structure-function relationship in the brain is necessary to know to what degree structural connectivity underpins abnormal functional connectivity seen in disorders. We integrated high-field resting-state fMRI-based functional connectivity with high-resolution macro-scale diffusion-based and meso-scale neuronal tracer-based structural connectivity, to obtain an accurate depiction of the structure-function relationship in the rat brain. Our main goal was to identify to what extent structural and functional connectivity strengths are correlated, macro- and meso-scopically, across the cortex. Correlation analyses revealed a positive correspondence between functional and macro-scale diffusion-based structural connectivity, but no significant correlation between functional connectivity and meso-scale neuronal tracer-based structural connectivity. Zooming in on individual connections, we found strong functional connectivity in two well-known resting-state networks: the sensorimotor and default mode network. Strong functional connectivity within these networks coincided with strong short-range intrahemispheric structural connectivity, but with weak heterotopic interhemispheric and long-range intrahemispheric structural connectivity. Our study indicates the importance of combining measures of connectivity at distinct hierarchical levels to accurately determine connectivity across networks in the healthy and diseased brain. Although characteristics of the applied techniques may affect where structural and functional networks (dis)agree, distinct structure-function relationships across the brain could also have a biological basis.

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Structure-Function Relationships in Brain-Injured Patients: A Scoping Review

10.31222/osf.io/wnhye ◽

2020 ◽

Author(s):

Nicholas Parsons ◽

Matthew Hughes ◽

Govinda Poudel ◽

Juan F. Dominguez D. ◽

Karen Caeyenberghs

Keyword(s):

Structure Function ◽

Scoping Review ◽

Brain Injuries ◽

Structural Connectivity ◽

Normal Structure ◽

Theoretical Frameworks ◽

Brain Injured ◽

Structure Function Relationship ◽

Function Relationship ◽

Injured Patients

The human brain is a dynamic network comprised of elements which are structurally connected and functionally interactive. A tight structure-function relationship is vital for this system to produce seamless cognition and behaviour. Brain injuries due to either neurological disease or single-event injuries alter the dynamics of normal structure-function interaction, resulting in poor neurobehavioural outcomes for patients. This scoping review is a synthesis of recent progress in understanding how brain injuries alter the structure-function relationship. We identified 16 studies that investigated the structure-function relationship in brain-injured cohorts, using fMRI and either T1-weighted or diffusion-weighted MRI to calculate, respectively, grey matter density or structural connectivity. Overall, a reduced structure-function relationship was found in brain-injured patients relative to healthy controls. This weakened relationship coincided with impaired cognition. Structural and functional MRI information should also be reconciled into suitable graph theoretical frameworks such as the multilayer network approach

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