Exposure to manganese during juvenile development increases microglial activation in the hippocampus following systemic infection with A/California/04/2009 Influenza A H1N1 virus

A/California/04/2009 H1N1. To assess histopathology following this exposure paradigm, we performed high-content microscopy and machine learning-based image analysis of H&E and IHC-stained sections spanning the hippocampus to quantify pyknotic neurons and reactive microglia. We report a significant increase in the number of pyknotic neurons in the dentate gyrus as well as morphologic changes in microglia that are consistent with inflammatory activation. Our findings highlight the capacity of combined juvenile manganese exposure and adult viral infection to induce substantial microgliosis in the hippocampus.