Regional Neural Activity Abnormalities and Whole-Brain Functional Connectivity Reorganization in Bulimia Nervosa: Evidence From Resting-State fMRI

Abstract

The management of eating behavior in bulimia nervosa (BN) patients is a complex process, and BN involves activity in multiple brain regions that integrate internal and external functional information. This functional information integration occurs in brain regions involved in reward, cognition, attention, memory, emotion, smell, taste, vision and so on. Although it has been reported that resting-state brain activity in BN patients is different from that of healthy controls, the neural mechanisms remain unclear and need to be further explored. The fractional amplitude of low-frequency fluctuation (fALFF) analyses are an important data-driven method that can measure the relative contribution of low-frequency fluctuations within a specific frequency band to the whole detectable frequency range. The fALFF is well suited to reveal the strength of interregional cooperation at the single-voxel level to investigate local neuronal activity power. FC is a brain network analysis method based on the level of correlated dynamics between time series, which establishes the connection between two spatial regions of interest (ROIs) with the assistance of linear temporal correlation. Based on the psychological characteristics of patients with BN and the abnormal brain functional activities revealed by previous neuroimaging studies, in this study, we investigated alterations in regional neural activity by applying fALFF analysis and whole-brain functional connectivity (FC) in patients with BN in the resting state and to explore correlations between brain activities and eating behavior. We found that the left insula and bilateral inferior parietal lobule (IPL), as key nodes in the reorganized resting-state neural network, had altered FC with other brain regions associated with reward, emotion, cognition, memory, smell/taste, and vision-related functional processing, which may have influenced restrained eating behavior. These results could provide a further theoretical basis and potential effective targets for neuropsychological treatment in patients with BN.

Altered connectivity patterns of medial and lateral orbitofrontal cortex underlie the severity of bulimic symptoms

“…The finding that the SB and MB groups both showed lower lOFC-SPL connectivity strength than HC is in accordance with the results of a previous resting-state fMRI study ( Wang et al., 2022 ). As crucial hubs of the frontoparietal network, the lOFC and SPL have been implicated in initiating and modulating cognitive control abilities, such as the downregulation of inhibition and reappraisal of food carving ( Hollmann et al., 2012 ; Siep et al., 2012 ; Zanto & Gazzaley 2013 ).…”

Alterations of interhemispheric functional homotopic connectivity and corpus callosum microstructure in bulimia nervosa

“…Parallelly, we previously reported increased OFC volume in BN patients ( 38 ). Mounting researches have proved the involvement of the OFC in the neural mechanism of BN from the perspectives in brain activation pattern ( 39 ), structural network properties ( 11 ) and FC ( 8 ). OFC is involved in hedonic food processing and plays a central role in food value-directed eating behavior ( 40 ).…”

“…Uher et al demonstrated diminished occipitotemporal responses in patients with BN when viewing their own abnormal body weight ( 7 ). Using the resting-state fMRI images (rs-fMRI), our previous study suggested aberrant regional activity in the left insula and bilateral inferior parietal lobule ( 8 ). Moreover, there is growing recognition that BN may result from abnormal information interaction between different functional centers or even across large-scale brain networks.…”

Aberrant modular segregation of brain networks in female patients with bulimia nervosa

“…Developing resting‐state functional magnetic resonance imaging (RS‐fMRI) technology has facilitated the discovery of neurobiological mechanisms of BN. Convergent evidence from RS‐fMRI has demonstrated that the bulimic behaviors in BN were associated not only with functional abnormalities in specific brain regions (Lavagnino et al, 2014; Li et al, 2022; Wang et al, 2022; Wang, Bi, et al, 2020) but also with disruptions in intrinsic functional brain networks (Amianto, D'Agata, et al, 2013; Li et al, 2018; Spalatro et al, 2019; Wang et al, 2017; Wang et al, 2019). In general, a healthy brain is an efficient network consisting of a series of highly functionally specialized and spatially separated modules (Ma et al, 2020).…”