The impact of polystyrene microplastics (PS-MPs) on the nervous system has been documented in the literature. Numerous studies have demonstrated that the activation of the epidermal growth factor receptor 4 (ErbB4) is crucial in neuronal injury and regeneration processes. This study investigated the role of targeted activation of ErbB4 receptor through a small molecule agonist, 4-bromo-1-hydroxy-2-naphthoic acid (C11H7BrO3, E4A), in mitigating PS-MPs-induced neuronal injury. The findings revealed that targeted activation of ErbB4 receptor significantly ameliorated cognitive behavioral deficits in mice exposed to PS-MPs. Furthermore, E4A treatment upregulated the expression of dedicator of cytokinesis 3 (DOCK3) and Sirtuin 3 (SIRT3) and mitigated mitochondrial and synaptic dysfunction within the hippocampus of PS-MPs-exposed mice. E4A also diminished the activation of the TLR4-NF-κB-NLRP3 signaling pathway, consequently reducing neuroinflammation. In vitro experiments demonstrated that E4A partially alleviated PS-MPs-induced hippocampal neuronal injury and its effects on microglial inflammation. In conclusion, the findings of this study indicate that targeted activation of ErbB4 receptor may mitigate neuronal damage and subsequent neuroinflammation, thereby alleviating hippocampal neuronal injury induced by PS-MPs exposure and ameliorating cognitive dysfunction. These results offer valuable insights for the development of potential therapeutic strategies.