The Unique Cytoarchitecture and Wiring of the Human Default Mode Network

It is challenging to specify the role of the default mode network (DMN) in human behaviour. Contemporary theories, based on functional magnetic resonance imaging (MRI), suggest that the DMN is insulated from the external world, which allows it to support perceptually-decoupled states and to integrate external and internal information in the construction of abstract meanings. To date, the neuronal architecture of the DMN has received relatively little attention. Understanding the cytoarchitectural composition and connectional layout of the DMN will provide novel insights into its role in brain function. We mapped cytoarchitectural variation within the DMN using a cortical type atlas and a histological model of the entire human brain. Next, we used MRI acquired in healthy young adults to explicate structural wiring and effective connectivity. We discovered profound diversity of DMN cytoarchitecture. Connectivity is organised along the most dominant cytoarchitectural axis. One side of the axis is the prominent receiver, whereas the other side remains more insulated, especially from sensory areas. The structural heterogeneity of the DMN engenders a network-level balance in communication with external and internal sources, which is distinctive, relative to other functional communities. The neuronal architecture of the DMN suggests it is a protuberance from the core cortical processing hierarchy and holds a unique role in information integration.

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Task-Dependent Modulation of Effective Connectivity within the Default Mode Network

Frontiers in Psychology ◽

10.3389/fpsyg.2012.00206 ◽

2012 ◽

Vol 3 ◽

Cited By ~ 44

Author(s):

Baojuan Li ◽

Xiang Wang ◽

Shuqiao Yao ◽

Dewen Hu ◽

Karl Friston

Keyword(s):

Default Mode Network ◽

Effective Connectivity ◽

Default Mode

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The role of the default mode network in component processes underlying the wandering mind

Social Cognitive and Affective Neuroscience ◽

10.1093/scan/nsx041 ◽

2017 ◽

Vol 12 (7) ◽

pp. 1047-1062 ◽

Cited By ~ 48

Author(s):

Giulia L. Poerio ◽

Mladen Sormaz ◽

Hao-Ting Wang ◽

Daniel Margulies ◽

Elizabeth Jefferies ◽

...

Keyword(s):

Default Mode Network ◽

Default Mode ◽

Component Processes

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Analysis of Default Mode Network in Social Anxiety Disorder: EEG Resting-State Effective Connectivity Study

10.20944/preprints202102.0610.v1 ◽

2021 ◽

Author(s):

Abdulhakim Al-Ezzi ◽

Nidal Kamel ◽

Ibrahima Faye ◽

Esther Gunaseli

Keyword(s):

Anxiety Disorder ◽

Social Anxiety ◽

Social Anxiety Disorder ◽

Default Mode Network ◽

Resting State ◽

Effective Connectivity ◽

Mean Values ◽

Default Mode ◽

Severe Group ◽

The Mean

Several neuroimaging findings by using different modalities (e.g., fMRI and PET) have suggested that social anxiety disorder (SAD) is correlated with alterations in regional or network-level brain function. However, these modalities do not quantify the fast dynamic connectivity of causal information networks due to their poor temporal resolution. In this study, SAD-related changes in brain connections within the default mode network (DMN) was investigated using Electroencephalogram (EEG). Partial directed coherence (PDC) was used to assess the causal influences of DMN regions on each other and indicate the changes in the DMN effective network related to SAD severity. The EEG data were collected from 88 subjects (control, mild, moderate, severe) and used to estimate the effective connectivity between DMN regions at different frequency bands. Among the healthy control (HC) and the three considered levels of severity of SAD, the results indicated a higher level of causal interactions for the mild and moderate SAD groups than for the severe and HC groups. Between the control and the severe SAD groups, the results indicated a higher level of causal connections for the control throughout all the DMN regions. We found significant increases in the mean PDC in the delta and alpha bands between the SAD groups. Among the DMN regions, the precuneus exhibited a higher level of causal influence than other regions. Therefore, it was suggested to be a major source hub that contributes to the mental exploration and emotional content of SAD. In contrast to the severe group, the HC exhibited higher resting-state connectivity at the mesial prefrontal cortex (mPFC), providing evidence for mPFC dysfunction in the severe SAD group. Furthermore, the total Social Interaction Anxiety Scale (SIAS) was positively correlated with the mean values of the PDC of the severe SAD group and negatively correlated with those of the HC group. The reported results may facilitate greater comprehension of the underlying potential SAD neural biomarkers and can be used to characterize possible targets for further medication.

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IC-P-031: EFFECTIVE CONNECTIVITY WITHIN THE DEFAULT MODE NETWORK IN MILD COGNITIVE IMPAIRMENT AND ALZHEIMER'S DISEASE

Alzheimer s & Dementia ◽

10.1016/j.jalz.2018.06.2095 ◽

2006 ◽

Vol 14 (7S_Part_1) ◽

pp. P35-P36

Author(s):

Cole John Cook ◽

Gyujoon Hwang ◽

Veena A. Nair ◽

Andrew L. Alexander ◽

Piero G. Antuono ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Default Mode Network ◽

Effective Connectivity ◽

Default Mode

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Trait self-reflectiveness relates to time-varying dynamics of resting state functional connectivity and underlying structural connectomes: Role of the default mode network

NeuroImage ◽

10.1016/j.neuroimage.2020.116896 ◽

2020 ◽

Vol 219 ◽

pp. 116896 ◽

Cited By ~ 4

Author(s):

Daouia I. Larabi ◽

Remco J. Renken ◽

Joana Cabral ◽

Jan-Bernard C. Marsman ◽

André Aleman ◽

...

Keyword(s):

Functional Connectivity ◽

Default Mode Network ◽

Resting State ◽

Time Varying ◽

Resting State Functional Connectivity ◽

Default Mode

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P291: Effective connectivity of the default mode network in Parkinson’s disease and Parkinson’s disease dementia

Clinical Neurophysiology ◽

10.1016/s1388-2457(14)50413-0 ◽

2014 ◽

Vol 125 ◽

pp. S126-S127 ◽

Cited By ~ 1

Author(s):

I. Rektorova ◽

L. Krajcovicova ◽

R. Marecek ◽

M. Mikl

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Default Mode Network ◽

Effective Connectivity ◽

Parkinson’S Disease Dementia ◽

Default Mode

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Temporal circuit of macroscale dynamic brain activity supports human consciousness

Science Advances ◽

10.1126/sciadv.aaz0087 ◽

2020 ◽

Vol 6 (11) ◽

pp. eaaz0087 ◽

Cited By ~ 11

Author(s):

Zirui Huang ◽

Jun Zhang ◽

Jinsong Wu ◽

George A. Mashour ◽

Anthony G. Hudetz

Keyword(s):

Default Mode Network ◽

Functional Role ◽

Brain Activity ◽

Human Consciousness ◽

Attention Network ◽

Attention Networks ◽

Default Mode ◽

Dorsal Attention Network ◽

Brain States

The ongoing stream of human consciousness relies on two distinct cortical systems, the default mode network and the dorsal attention network, which alternate their activity in an anticorrelated manner. We examined how the two systems are regulated in the conscious brain and how they are disrupted when consciousness is diminished. We provide evidence for a “temporal circuit” characterized by a set of trajectories along which dynamic brain activity occurs. We demonstrate that the transitions between default mode and dorsal attention networks are embedded in this temporal circuit, in which a balanced reciprocal accessibility of brain states is characteristic of consciousness. Conversely, isolation of the default mode and dorsal attention networks from the temporal circuit is associated with unresponsiveness of diverse etiologies. These findings advance the foundational understanding of the functional role of anticorrelated systems in consciousness.

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