Fig. 6.
Abnormalities of midline crossing of the corpus callosum in the Csf1r−/− mice. (A) P20 forebrain sections immunostained for MBP, showing the failure of the callosal axons to cross the midline in the Csf1r−/− brains (white arrow). Asterisk indicates the formation of the Probst bundles (P). (B) Apoptosis of GFAP+ cells in the IG and along the midline of E15.5 Csf1r−/− dorsal forebrains. Overlap of active caspase-3 (red) with GFAP (blue) staining, but not with NeuN (green) staining. (C) Expression of IL-34 and the CSF-1R at the midline and the IG of E15.5 dorsal forebrains. Upper panels: Immunostaining reveals the expression of IL-34 (red, left) and the CSF-1R (red, middle and right). Note the presence of CSF-1R+(red) Iba1+(green) microglia (middle). A subset of GFAP+ (green) population also expresses the CSF-1R (red, right). Lower panels: Insets 1 and 2 from upper panels. Arrows indicate overlap of CSF-1R staining with Iba1 and GFAP staining. Dotted line indicates the contour of each hemisphere. CC, corpus callosum; IG, indusium griseum.