Figure 2.

Distribution of excitatory and inhibitory presynaptic terminals onto PV⁺ and CR⁺ INs in P56 Mecp2 KO mice. Representative confocal images of VGLUT1⁺ (green: A, C) and VGAT⁺ (blue: B, D) puncta corresponding to excitatory and inhibitory presynaptic terminals, respectively, apposed to dendrites (top) and somata (bottom) of PV⁺ INs in layer II/III of S1 cortex in P56 WT and Mecp2 KO mice. Histograms showing quantitative analysis in WT and Mecp2 KO mice of VGLUT1⁺ and VGAT⁺ puncta density contacting either dendrites (E, F) or somata (G, H), respectively, of PV⁺ INs. Confocal images showing VGLUT1⁺ (green: I, K) and VGAT⁺ (blue: J, L) puncta contacting dendrites (top) and somata (bottom) of CR⁺ INs in layer II/III of S1 cortex in WT and Mecp2 KO mice. Histograms showing quantitative analysis in WT and Mecp2 KO mice of VGLUT1⁺ and VGAT⁺ puncta density contacting either dendrites (M, N) or somata (O, P), respectively, of CR⁺ INs. PV: VGLUT1 n = 6 mice per genotype; VGAT dendrites n = 5 WT and 4 Mecp2 KO mice per genotype; VGAT soma n = 5 mice per genotype; CR: VGLUT1 n = 6 mice and VGAT n = 5 mice per genotype. Student’s t test: *p < 0.05; **p < 0.01. Q, Representative 3D projections in three image planes showing excitatory VGLUT1⁺ (green) and inhibitory VGAT⁺ (blue) synaptic terminals contacting PV⁺ cell bodies and dendrites (red). Arrowheads point to selected VGLUT1⁺ and VGAT⁺ puncta apposed to dendrites or somata of PV⁺ interneurons at the intersection of the XY cross. Note the lack of black pixels between the presynaptic puncta and the postsynaptic structures. Scale bars = 5 μm.