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Kuramoto model simulation of neural hubs and dynamic synchrony in the human cerebral connectome.

Schmidt R, LaFleur KJ, de Reus MA, van den Berg LH, van den Heuvel MP - BMC Neurosci (2015)

Bottom Line: Furthermore, suppressing structural connectivity among hub nodes resulted in an elevated modular state (p < 4.1 × l0(-3), 0.015 < λ < 0.04), indicating that hub-to-hub connections are critical in intermodular synchronization.Finally, perturbing the oscillatory behavior of hub nodes prevented functional modules from synchronizing, implying that synchronization of functional modules is dependent on the hub nodes' behavior.Our results converge on anatomical hubs having a leading role in intermodular synchronization and integration in the human brain.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Heidelberglaan 100, PO Box 85500, 3508 GA, Utrecht, Netherlands. r.schmidt@umcutrecht.nl.

ABSTRACT

Background: The topological structure of the wiring of the mammalian brain cortex plays an important role in shaping the functional dynamics of large-scale neural activity. Due to their central embedding in the network, high degree hub regions and their connections (often referred to as the 'rich club') have been hypothesized to facilitate intermodular neural communication and global integration of information by means of synchronization. Here, we examined the theoretical role of anatomical hubs and their wiring in brain dynamics. The Kuramoto model was used to simulate interaction of cortical brain areas by means of coupled phase oscillators-with anatomical connections between regions derived from diffusion weighted imaging and module assignment of brain regions based on empirically determined resting-state data.

Results: Our findings show that synchrony among hub nodes was higher than any module's intramodular synchrony (p < 10(-4), for cortical coupling strengths, λ, in the range 0.02 < λ < 0.05), suggesting that hub nodes lead the functional modules in the process of synchronization. Furthermore, suppressing structural connectivity among hub nodes resulted in an elevated modular state (p < 4.1 × l0(-3), 0.015 < λ < 0.04), indicating that hub-to-hub connections are critical in intermodular synchronization. Finally, perturbing the oscillatory behavior of hub nodes prevented functional modules from synchronizing, implying that synchronization of functional modules is dependent on the hub nodes' behavior.

Conclusion: Our results converge on anatomical hubs having a leading role in intermodular synchronization and integration in the human brain.

No MeSH data available.


Related in: MedlinePlus

Macaque verification of hub connectivity suppression and perturbation effects. Suppressing hub connectivity in the macaque cortical network verified the result of increased modularity found in the human cerebral cortex network (Fig. 4). Throughout the critical regime modules were found to have increased intramodular synchrony when hub connectivity was suppressed pointing at the important role of hub nodes in establishing intermodular and global synchrony (a). Similar to the effects observed in the human network (Fig. 5), perturbing the internal frequencies of the hub nodes in the macaque cortical network prevented the modules from synchronizing (b). Perturbation of an equally large random set of nodes (c) or a module (d) did not keep the unperturbed part of the network from synchronizing, underlining the importance of the hub nodes in intermodular communication and integration
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Fig6: Macaque verification of hub connectivity suppression and perturbation effects. Suppressing hub connectivity in the macaque cortical network verified the result of increased modularity found in the human cerebral cortex network (Fig. 4). Throughout the critical regime modules were found to have increased intramodular synchrony when hub connectivity was suppressed pointing at the important role of hub nodes in establishing intermodular and global synchrony (a). Similar to the effects observed in the human network (Fig. 5), perturbing the internal frequencies of the hub nodes in the macaque cortical network prevented the modules from synchronizing (b). Perturbation of an equally large random set of nodes (c) or a module (d) did not keep the unperturbed part of the network from synchronizing, underlining the importance of the hub nodes in intermodular communication and integration

Mentions: Hub connectivity suppression Simulations in which hub connectivity was suppressed showed increased modularity (higher intramodular to global synchrony ratio, p < 10−4, 0.01 < λ < 0.03) compared with the removal of an equal sized random set of connections (Fig. 6a).Fig. 6


Kuramoto model simulation of neural hubs and dynamic synchrony in the human cerebral connectome.

Schmidt R, LaFleur KJ, de Reus MA, van den Berg LH, van den Heuvel MP - BMC Neurosci (2015)

Macaque verification of hub connectivity suppression and perturbation effects. Suppressing hub connectivity in the macaque cortical network verified the result of increased modularity found in the human cerebral cortex network (Fig. 4). Throughout the critical regime modules were found to have increased intramodular synchrony when hub connectivity was suppressed pointing at the important role of hub nodes in establishing intermodular and global synchrony (a). Similar to the effects observed in the human network (Fig. 5), perturbing the internal frequencies of the hub nodes in the macaque cortical network prevented the modules from synchronizing (b). Perturbation of an equally large random set of nodes (c) or a module (d) did not keep the unperturbed part of the network from synchronizing, underlining the importance of the hub nodes in intermodular communication and integration
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4556019&req=5

Fig6: Macaque verification of hub connectivity suppression and perturbation effects. Suppressing hub connectivity in the macaque cortical network verified the result of increased modularity found in the human cerebral cortex network (Fig. 4). Throughout the critical regime modules were found to have increased intramodular synchrony when hub connectivity was suppressed pointing at the important role of hub nodes in establishing intermodular and global synchrony (a). Similar to the effects observed in the human network (Fig. 5), perturbing the internal frequencies of the hub nodes in the macaque cortical network prevented the modules from synchronizing (b). Perturbation of an equally large random set of nodes (c) or a module (d) did not keep the unperturbed part of the network from synchronizing, underlining the importance of the hub nodes in intermodular communication and integration
Mentions: Hub connectivity suppression Simulations in which hub connectivity was suppressed showed increased modularity (higher intramodular to global synchrony ratio, p < 10−4, 0.01 < λ < 0.03) compared with the removal of an equal sized random set of connections (Fig. 6a).Fig. 6

Bottom Line: Furthermore, suppressing structural connectivity among hub nodes resulted in an elevated modular state (p < 4.1 × l0(-3), 0.015 < λ < 0.04), indicating that hub-to-hub connections are critical in intermodular synchronization.Finally, perturbing the oscillatory behavior of hub nodes prevented functional modules from synchronizing, implying that synchronization of functional modules is dependent on the hub nodes' behavior.Our results converge on anatomical hubs having a leading role in intermodular synchronization and integration in the human brain.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Heidelberglaan 100, PO Box 85500, 3508 GA, Utrecht, Netherlands. r.schmidt@umcutrecht.nl.

ABSTRACT

Background: The topological structure of the wiring of the mammalian brain cortex plays an important role in shaping the functional dynamics of large-scale neural activity. Due to their central embedding in the network, high degree hub regions and their connections (often referred to as the 'rich club') have been hypothesized to facilitate intermodular neural communication and global integration of information by means of synchronization. Here, we examined the theoretical role of anatomical hubs and their wiring in brain dynamics. The Kuramoto model was used to simulate interaction of cortical brain areas by means of coupled phase oscillators-with anatomical connections between regions derived from diffusion weighted imaging and module assignment of brain regions based on empirically determined resting-state data.

Results: Our findings show that synchrony among hub nodes was higher than any module's intramodular synchrony (p < 10(-4), for cortical coupling strengths, λ, in the range 0.02 < λ < 0.05), suggesting that hub nodes lead the functional modules in the process of synchronization. Furthermore, suppressing structural connectivity among hub nodes resulted in an elevated modular state (p < 4.1 × l0(-3), 0.015 < λ < 0.04), indicating that hub-to-hub connections are critical in intermodular synchronization. Finally, perturbing the oscillatory behavior of hub nodes prevented functional modules from synchronizing, implying that synchronization of functional modules is dependent on the hub nodes' behavior.

Conclusion: Our results converge on anatomical hubs having a leading role in intermodular synchronization and integration in the human brain.

No MeSH data available.


Related in: MedlinePlus