This 3D reconstruction of immunofluorescence staining shows microglial cell activation (Green, Iba1 marker) 30 days after an embolic stroke, with infiltration of the hippocampal formation and reduced density of synaptic connections (Red, SV-2) among neurons (Magenta, NeuN). This invasion can be inhibited by early targeting of the complement components of innate immunity. For more information, see the article by Alawieh et al. (pages 4042–4058).