Parcellation‐based tractographic modeling of the salience network through meta‐analysis

Abstract

Background:The salience network (SN) is a transitory mediator between active and passive states of mind. Multiple cortical areas, including the opercular, insular, and cingulate cortices have been linked in this processing, though knowledge of network connectivity has been devoid of structural specificity. Objective:The current study sought to create an anatomically specific connectivity model of the neural substrates involved in the salience network.Methods: A literature search of PubMed and BrainMap Sleuth was conducted for resting-state and task-based fMRI studies relevant to the salience network according to PRISMA guidelines. Publicly available meta-analytic software was utilized to extract relevant fMRI data for the creation of an activation likelihood estimation (ALE) map and relevant parcellations from the human connectome project overlapping with the ALE data were identified for inclusion in our SN model. DSI-based fiber tractography was then performed on publicaly available data from healthy subjects to determine the structural connections between cortical parcellations comprising the network.Results: Nine cortical regions were found to comprise the salience network: areas AVI (anterior ventral insula), MI (middle insula), FOP4 (frontal operculum 4), FOP5 (frontal operculum 5), a24pr (anterior 24 prime), a32pr (anterior 32 prime), p32pr (posterior 32 prime), and SCEF (supplementary and cingulate eye field), and 46. The frontal aslant tract was found to connect the opercular-insular cluster to the middle cingulate clusters of the network, while mostly short U-fibers connected adjacent nodes of the network. Conclusion:Here we provide an anatomically specific connectivity model of the neural substrates involved in the salience network. These results may serve as an empiric basis for clinical translation in this region and for future study which seeks to expand ourThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

A parcellation‐based connectomic model of hemispatial neglect

“…Parcellations 46 and p9‐46v overlap with the neglect ROIs in this area 46 . Importantly, these regions correspond to the mid‐dorsolateral prefrontal cortex and have been associated with the salience network and central executive networks 44 . As such, previous work on this region suggests its importance with the attentional processing and the conscious, active control of planned behavior supporting a likely relationship between damage to this region and the impairments which manifest in hemispatial neglect 54–56 .…”

“…with the salience network and central executive networks. 44 As such, previous work on this region suggests its importance with the attentional processing and the conscious, active control of planned behavior supporting a likely relationship between damage to this region and the impairments which manifest in hemispatial neglect. [54][55][56] The anatomic connectivity of the MFG has been described by our team in detail previously.…”

“…We used BrainMap GingerALE (v. 2.3.6, BrainMap, San Antonio, US, https://brainmap.org/index.html) to extract the relevant MRI data for the creation of ALEs of key brain regions implicated in neglect using anatomical likelihood estimation analysis 29,42,43 as previously described by our team. 44,45 All Talairach coordinates identified during the literature review were converted to the MNI coordinate space using SPM Conversion in GingerALE. 29,42 We performed a Single Study analysis using Cluster-Level Inference in the MNI coordinate space (cluster level of 0.05, threshold permutations of 1000, uncorrected p of .001).…”

Topology of the lateral visual system: The fundus of the superior temporal sulcus and parietal area H connect nonvisual cerebrum to the lateral occipital lobe

“…For instance, in Table 3 , a great deal of variability can be seen in the relative fiber volume within identified subjects. While this may raise concerns about the relative strength and therefore importance of specific connections, it must be reminded that the relative strength of tractographic analyses is the ability to qualitatively demonstrate the nature of the more common white matter connections between ROIs, which can clarify specific connections that may support possible known functional relevance in connected regions or provide areas of basis for future study (Briggs et al., 2022 ; Essayed et al., 2017 ). Therefore, our quantitative analyses should be interpreted cautiously within the context of these known limitations, and further and more rigorous analyses on these connections are necessary to better clarify their relative strength and interindividual differences.…”

Connectomic Networks and Their Impact on Clinical Outcomes in Glioma Treatment: A Review

“…The SN comprises the ventrolateral prefrontal cortex (VLPFC), dorsal ACC, and anterior insula. 49,50 The SN is used in modulating activation of the DMN and CEN by detecting the presence of salient stimuli (cognitive, homeostatic, or emotional). 30,49,[51][52][53][54] Specifically, Goulden et al 52 confirmed that the SN is vital to switching between the CEN and DMN.…”