A novel role of Arp2/3 complex in the forgetting behavior of <i>Caenorhabditis elegans</i> to <i>Pseudomonas aeruginosa</i> PA14

Forgetting behavior is a common phenomenon that has been widely studied in various model organisms, including <i>Caenorhabditis elegans</i> (<i>C. elegans</i>), Drosophila, and mammals such as mice and humans. Understanding the mechanisms underlying forgetting can provide valuable insights into potential treatments for memory-related disorders. In this study, <i>C. elegans</i> was used as a model organism to establish a forgetting model based on the PA14 pathogen. A proteomic analysis of signaling pathways involved in forgetting revealed the role of the Arp2/3 complex in regulating pathogen-induced forgetting. Manipulation of genes encoding the components of the Arp2/3 complex (<i>arx-1</i>, <i>arx-2</i>, <i>arx-3</i>, <i>arx-5</i>, and <i>arx-7</i>) led to a reduction in the duration of pathogen-induced forgetting. Additionally, one hour after pathogen removal, a significant decrease in the mRNA levels of <i>arx-5</i> and <i>arx-7</i> was observed, along with a reduction in <i>arx-2::mCherry</i> fluorescence in specific tissues of <i>C. elegans</i>. This study demonstrates that <i>C. elegans</i> exhibits forgetting behavior towards PA14, with a forgetting duration of approximately 2 hours. Pathogen-induced forgetting is associated with an increase in heterogeneous proteins localized to the cytoskeleton. Moreover, the expression levels of genes related to the Arp2/3 complex (<i>arx-1</i>, <i>arx-2</i>, <i>arx-3</i>, <i>arx-5</i>, and <i>arx-7</i>) are reduced, inhibiting cytoskeleton nucleation in cells. This inhibition may contribute to the observed pathogen-induced forgetting in <i>C. elegans</i> in response to PA14.