Silicon Dioxide Nanoparticles Alter Social Behavior, Color Preference, Oxidative Stress Markers, and Histological Structure of Brain Regions in Zebrafish (Danio rerio)

Silicon dioxide nanoparticles (SiO₂NPs) are widely used in various industries, raising concerns about their potential toxicity in aquatic organisms. Although several studies have investigated the general toxic effects of SiO₂NPs, little is known about their impact on the nervous system and behavior of aquatic vertebrates. Furthermore, the combined assessment of behavioral, histological, and biochemical responses remains scarce. The study aimed to evaluate the effects of SiO₂NPs on behavioral, histological, and biochemical parameters in adult zebrafish (<i>Danio rerio</i>). Fish were exposed to sublethal concentrations of SiO₂NPs and their behavior was assessed using the social interaction test and the color preference test. Significant alterations in social behavior, such as reduced group cohesion and increased isolation tendencies, were observed. Additionally, exposed zebrafish exhibited a marked shift in color preference, indicating potential disruptions in sensory or cognitive function. Histological analyses revealed dose dependent tissue changes in brain structures, while biochemical assays indicated reduced activity of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), suggesting elevated oxidative stress (OS). To the best of our knowledge, this is one of the first studies to integrate behavioral, histological, and biochemical endpoints in zebrafish to assess the neurotoxic potential of SiO₂NPs. These findings suggest that SiO₂NPs can induce histological alterations in brain structures, neurobehavioral changes, and OS in zebrafish, underscoring the novelty and relevance of this interdisciplinary approach, and the importance of further studies on SiO₂NPs environmental and health impacts.