Figure S7.

Microglia engulf fibronectin 1 during CSA lesion repair, related to Figure 7

(A) Fibronectin 1 (FN1) signal after immunostaining accumulates at the P3 resorbing CSA in Cx3cr1^gfp/+ pups prenatally exposed to PLX3397 in both repopulating microglia and in the tissue surrounding them, whereas little FN1 signal is detected beyond blood vessels in controls. Dotted boxes represent the areas in which the intensity of the FN1 signal in the extracellular space was measured in the CSA, neocortex (Ncx) and amygdala (Am). The quantification (right) shows the intensity of CSA FN1 signal, normalized relative to the mean of neocortex and amygdala signals in both controls and prenatally exposed PLX3397 pups (n_controls = 4; n_PLX3397 = 4, from at least two distinct litters).

(B) High magnification and 3D reconstruction of CSA microglia identified as Cx3cr1^gfp-positive cells show a slight increase in the volume of FN1 inside microglia (n_controls = 4 mice; n_PLX3397 = 4 mice; from at least two distinct litters and at least 2 cells quantified and averaged per animal) and a significant increase in the number of microglia with FN1 inclusions in P3 resorbing brains compared with controls (n_controls = 4; n_PLX3397 = 5; mice from at least two distinct litters). Graphs show means ± SEM. Mann-Whitney U test was performed for statistical comparison, ^∗p < 0.05; ns, non significant (p > 0.05). Scale bars: 100 μm in (A); 5 μm in (B, immunolabelings); and 2 μm in (3D reconstructions).

Am, amygdala; CSA, cortico-striato-amygdalar boundary; Ncx, neocortex.