Fig. 5.

Microglia restrain astrocytic activity after FCSD (A), Representative hippocampal GFAP staining for astrocytes in 14–20 week old mice at baseline (top) and after FCSD (bottom) with microglia (left) and with microglia ablated (right) to illustrate increase in reactivity following FCSD. Scale bar = 50 μM. Images were passed through a standardized threshold. (B), Quantification of (A); the percent area of a 500 × 500 μm region of CA3 hippocampus covered by GFAP astrocytic staining. n = 10-15 slices per mouse, 4 mice per condition. Statistical analysis performed using nonparametric Mann-Whitney test between relevant conditions. (C), Representative CA3 PSD95 (red) + GFAP (green) double stain with DAPI (blue). Images illustrating the difference between control (left) and ablated (right) conditions after FCSD. Arrows indicate colocalization of astrocytes and PSD95 marks after standardized thresholding, as defined by the JaCOP FIJI program. Different cohorts of mice were used for each condition. Scale bar = 20 μm. (D), Quantification of (C). Percent of PSD95 puncta in the DG to CA3 transition region contacted by astrocytic ramifications. GFAP and PSD95 were imaged in different fluorescent channels, passed through a standardized threshold, and overlaps measured by FIJI's colocalization plugin. Data expressed as mean ± SD. n = 4 mice per condition. Statistical analysis performed using an unpaired parametric two-tailed student's T test between relevant conditions. Related Fig. S5 displays further measured features of synaptic maturity and astrocytic reactivity. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)