Development and analysis of the adverse outcome pathway network for neurotoxicity

Adverse Outcome Pathways (AOPs) and their networks offer a structured framework for understanding toxicological mechanisms and supporting non-animal testing strategies. This study developed a neurotoxicity-focused AOP network (NT-AOPn) based on AOP-Wiki data and analyzed its topological properties using graph theory. We identified key events with high connectivity and centrality-such as oxidative stress and decreased thyroxine-and determined the two most prevalent adverse outcomes: Impairment of Learning and Memory (ILM) and Decreased Cognitive Function (CFD). Further analysis of their subnetworks revealed system-level perturbations spanning metabolic, neurological, and reproductive systems, and uncovered two novel AOP pathways linking molecular initiating events to adverse outcomes. Additionally, chemical stressors including heavy metals and pesticides were associated with these pathways. Our findings enhance the mechanistic understanding of neurotoxicity and provide a foundation for in vitro assays and computational modeling in risk assessment.