Bridging large-scale cortical networks: Integrative and function-specific hubs in the thalamus

Abstract

Summary The thalamus is critical for the brain's integrative hub functions; however, the localization and characterization of the different thalamic hubs remain unclear. Using a voxel-level network measure called functional connectivity overlap ratio (FCOR), we examined the thalamus' association with large-scale resting-state networks (RSNs) to elucidate its connector hub roles. Connections to the core-neurocognitive networks were localized in the anterior and medial parts, such as the anteroventral and mediodorsal nuclei areas. Regions functionally connected to the sensorimotor network were distinctively located around the lateral pulvinar nucleus but to a limited extent. Prominent connector hubs include the anteroventral, ventral lateral, and mediodorsal nuclei with functional connections to multiple RSNs. These findings suggest that the thalamus, with extensive connections to most of the RSNs, is well placed as a critical integrative functional hub and could play an important role for functional integration facilitating brain functions associated with primary processing and higher cognition.

The spatial extent of anatomical connections within the thalamus varies across the cortical hierarchy in humans and macaques

“…S1 for all nuclei labels and subgroup assignments. Anterior and medial thalamic nuclei are commonly associated with higher-order cognitive functions, while lateral and posterior nuclei are primarily associated with sensorimotor cognitive functions (8, 42, 60, 61). Similarly, ‘first-order’ thalamic nuclei relay sensory information to the cortex.…”

Involvement of cerebellar and subcortical connector hubs in schizophrenia

“…Specifically, they identified integration zones in the ventral intermediate thalamus for cingulo-opercular control and somatomotor networks and the pulvinar for dorsal attention and visual networks. We have also recently identified similar connector hub regions in the anterior insula, thalamus, and cerebellum ( Bagarinao et al, 2020 , Kawabata et al, 2021 ). These findings demonstrate the crucial role of connector hubs—located in the cerebral cortex, cerebellum, and subcortical regions—in the pathophysiology of schizophrenia.…”

“…In this study, we examined changes in the whole-brain connectivity in patients with schizophrenia using a network metric called functional connectivity overlap ratio (FCOR) ( Bagarinao et al, 2020 ). By quantifying a voxel’s connections to specific RSNs, FCOR can be used to identify regions with high between-network connectivity at the voxel level, enabling the identification of connector hubs across the whole brain ( Bagarinao et al, 2020 ), including the cerebellum ( Kawabata et al, 2022 ) and other subcortical regions ( Kawabata et al, 2021 ). Using resting-state fMRI data, FCOR maps for several well-known RSNs were generated and used to examine and compare connectivity changes across the whole brain between patients with schizophrenia and control groups.…”

Spatiotemporal patterns of sleep spindle activity in human anterior thalamus and cortex

“…The thalamus is richly connected with cortical and subcortical structures (Cappe, Morel, Barone, & Rouiller, 2009; Jankowski et al, 2013; Zhang, Snyder, Shimony, Fox, & Raichle, 2010) and has been proposed as a connector hub between distinct cortical networks (Kawabata et al, 2021). Recent research hints at an active role of the thalamus in memory consolidation during sleep (Klinzing et al, 2019).…”