Integrated Profiling of Synaptic E/I Balance Reveals Altered Synaptic Organization and Phenotypic Variability in a Prenatal ASD Model

Abstract

Proper regulation of excitation and inhibition (E/I balance) is essential for maintaining stable neural circuit function and flexible behavior. Disruptions of E/I balance have been implicated in a variety of neurodevelopmental and psychiatric disorders, including autism spectrum disorder (ASD). However, despite advances in connectomics and molecular neuroscience, how localized disruptions in E/I balance within cortical laminar architectures contribute to behavioral abnormalities remains to be elucidated. Here, we developed a standardized analysis pipeline that combines depth-aligned synaptic mapping, perspective and logarithmic transformations, and multivariate behavioral profiling. Applying this approach to a prenatal valproic acid (VPA) exposure model of ASD, we identified depth-specific disruptions of excitatory and inhibitory synaptic organization within the anterior cingulate cortex (ACC), alongside impairments in social behavior. Principal component analysis (PCA) integrating synaptic and behavioral parameters revealed convergent abnormalities that robustly distinguished VPA-exposed mice from wild-type (WT) controls. Furthermore, although still at an exploratory stage, our findings demonstrate that the robustness of this pipeline enables both the identification of resilient individuals and the quantification of intervention effects. Together, our findings establish a new cross-level analytical framework linking synaptic organization to organismal behavior and provide insights into circuit-level mechanisms underlying ASD-related phenotypes.