Astrocyte-specific Drp1 cKO mouse characterization. (A) Representative images of Drp1 cWT and cKO V1 cortices with tdTomato⁺ astrocytes (magenta) stained with Drp1 (yellow) and showing Drp1 masked by tdTomato (last column) at P21. Scale Bar, 40 µm. (B and C) Quantification of Drp1 mean gray value within tdTomato area normalized to astrocyte density per cortical layer (B) and across the whole cortex (C). N = 3–4 male and female mice/condition, 2–3 cortical images/mouse. Data points are mean ± SEM. Two-way ANOVA with Sidak’s multiple comparisons test for B, and an unpaired, two-tailed t test for C. (D) Quantification of cortical thickness in Drp1 cKO compared with cWT mice. N = 4 male and female mice/condition (large circles), n = 2–3 cortical images/mouse (small gray dots). Data are mean ± SEM. Unpaired, two-tailed t test. (E) Representative images of Drp1 cWT and cKO V1 cortices with tdTomato⁺ astrocytes (magenta) stained with Sox9 (green) at P21. Scale Bar, 100 µm. (F and G) Quantification of (F) percent Sox9 and tdTomato double-positive astrocytes out of total Sox 9-positive nuclei and (G) total Sox 9-positive nuclei per cortical field of view in Drp1 cWT and cKO mice. N = 3 male and female mice/condition (large circles), n = 3 cortical images/mouse (small gray dots). Data points are mean ± SEM. Nested t test. (H and I) Quantification of (H) Serpina3n and (I) Cp mRNA from immunopurified astrocytes from Drp1 cWT and cKO mice. N = 6 male and female mice/condition. Data are mean ± SEM. Unpaired two-tailed t test.