Axons express TLR7 during development of the brain.

<p>(<b>A</b>) Immunostaining of brain sections from C57Bl/6J mice on P12 and P5m using an antibody against TLR7. An overview and higher magnification images (*, **, ***, ****) displaying TLR7 expression in various brain regions are shown. CPu: caudate putamen; <b>LSD</b>: dorso-<b>lateral</b> septum; ff: fimbria, fornix; cc: corpus callosum. (<b>B</b>) Brain sections from P12 mice were co-immunostained with antibodies against TLR7 and neurofilament and subsequently were analyzed by confocal sequential microscopy. An overview and a higher magnification image (*) displaying TLR7 expression in the striatum are shown. Scale bar, 100 µm. (<b>C</b>) Brain sections from P12 mice were co-immunostained with antibodies against TLR7 and GFAP, RIP, or Iba1 to mark astrocytes, oligodendrocytes, and microglia in the corpus callosum, respectively. Subsequently, immunostained brain sections were analyzed by confocal sequential microscopy. Scale bar, 10 µm.