MMP3 and infection: Our data show that concomitantly with the up-regulation of the microglia associated transcripts (CD68 and AIF-1), the released "On" signals matrix-metalloproteinase-3 (MMP-3) and CXCL10 are up-regulated in the acute phase (1 day after infection) of the disease, whereas the released "Off" signal CX3CL1 is down-regulated.