Our results provided evidence that after H7N7 infection, the engulfment of Homer-1-labeled excitatory postsynaptic terminals into lysosomal compartments of microglial cells increased to some extent in both subregions of the hippocampus of young mice, but more strongly in the dentate gyrus of older mice, which may reflect the reduced dendritic spines in this subregion in both cohorts, as Homer-1 is a postsynaptic density (PSD) scaffold protein involved in synaptic plasticity (Tao-Cheng et al., 2014). Here, HOMER1 is linked to infection.