Structure-function coupling reveals the excitation-inhibition imbalance in autism spectrum disorder: A perspective from large-scale whole-brain network modeling.

Scientists used brain imaging and computer models to study how brain signals work differently in autism. They found that autistic brains show less flexible thinking patterns and different electrical activity. The balance between brain excitation and inhibition was disrupted at multiple levels, from individual brain regions to whole brain networks. This imbalance was directly linked to how different brain areas communicate with each other.

This neuroimaging study used computational modeling to investigate excitation-inhibition (E-I) balance in autism spectrum disorder (ASD). Researchers integrated structural and functional MRI data to construct whole-brain network models comparing individuals with ASD to healthy controls. Key findings included stronger structural-functional connectivity coupling in ASD, suggesting reduced cognitive flexibility. The study identified altered network dynamics, shifted neural oscillations (increased delta, decreased alpha activity), and heterogeneous reductions in E-I ratios across multiple brain scales.

A significant negative correlation was found between E-I ratio and structural-functional coupling, establishing a direct link between E-I dysregulation and abnormal brain network integration in ASD.

Findings support the excitation-inhibition imbalance theory in autism and may inform development of targeted interventions. The identified neural signatures could potentially serve as biomarkers for autism diagnosis or treatment monitoring, though further validation is required.

Sample size not reported. Single study using computational modeling approach. Unclear methodological details from abstract alone. Cross-sectional design cannot establish causality. Validation of modeling findings with direct neural measurements needed.

Excitation-inhibition (E-I) imbalance is a core pathological mechanism in autism spectrum disorder (ASD). However, current research on how E-I balance changes in ASD remains highly controversial. In this study, we integrate structural and functional magnetic resonance imaging data from the UCLA Multimodal Connectivity Database to construct a large-scale whole-brain network model, aiming to investigate the potential neural mechanism of E-I imbalance in ASD. We find that compared with healthy controls, patients with ASD exhibit stronger structural-functional connectivity (SC-FC) coupling, suggesting impaired cognitive flexibility.

Model analysis demonstrates altered network dynamics in ASD, characterized by reduced optimal coupling strength between empirical and simulated FC and a lower small-world index in simulated functional networks. Furthermore, a marked shift in neural oscillations is observed in ASD, including increased activity in the δ band and decreased activity in the α band, consistent with clinical findings. More importantly, our study reveals heterogeneous reductions of the E-I ratio in ASD across multiple spatial scales, spanning from local brain regions to large-scale networks, particularly highlighting a significant negative correlation between E-I ratio and SC-FC coupling. These findings establish a direct link between E-I dysregulation and abnormal structure-function integration in brain networks, providing novel insights into the complex pathogenesis underlying ASD.