Atypical high-PV-network configuration in the M1 cortex of Mecp2 KO mice. A, Representative images showing PV expression in layer II/III of M1 cortex in both WT and Mecp2 KO mice at P56. Histograms showing quantitative analysis of PV+ cell density at P56 (B), PV mean fluorescence intensity (C), cumulative (D) and binned (E) frequency distribution of PV cells intensity in WT and Mecp2 KO mice. F, Representative images showing PV expression in layer II/III of M1 cortex in both WT and Mecp2 KO mice at P28. Histograms showing quantitative analysis of PV cell density (G), PV mean fluorescence intensity (H), cumulative (I) and binned (J) frequency distribution of PV cells intensity in WT and Mecp2 KO mice at P28. n = 6 mice per genotype at P56 and n = 4 mice per genotype at P28. Student’s t test: *p < 0.05, **p < 0.01, Mann–Whitney U test for D, I: #p < 0.05; ##p < 0.01. Scale bars = 100 μm.