Panel A shows microscopy images of ChAT and VGluT2 signals in WT motor neuron somata. Panel B shows microscopy images of ChAT and VGluT2 signals in C3 deficient motor neuron somata. Panel C shows microscopy images of ChAT and VGluT2 signals in CD47 deficient motor neuron somata. Panel D shows bar graph quantifying VGluT2 synapses per motor neuron soma across genotypes. Panel E shows microscopy images of ChAT and GAD65/67 signals in WT motor neuron somata. Panel F shows microscopy images of ChAT and GAD65/67 signals in C3 deficient motor neuron somata. Panel G shows microscopy images of ChAT and GAD65/67 signals in CD47 deficient motor neuron somata. Panel H shows bar graph quantifying GAD65/67 synapses per motor neuron soma across genotypes.
Effects of genetic deletion of C3 and CD47 on excitatory VGluT2 and inhibitory GAD65/67 synaptic refinement. (A–C) Single optical plane confocal images from L4 motor neurons at P5. Immunoreactivity for ChAT (blue) and VGluT2+ (white) synapses in WT, C3−/− (B), and CD47−/− (C) mice (scale bars in A, B, and C are all 50 μm). Insets show higher magnification of a single motor neuron with VGluT2+ synapses (scale bar: 10 μm). (D) Quantification of VGluT2+ synapses on the entire motor neuron soma for each genotype. Data points (in grey) on graphs show individual motor neurons; colored data points represent the average value from each mouse. (E–G) Single optical plane confocal images from L4 motor neurons at P5. Immunoreactivity for ChAT (blue) and GAD65/67+ (white) synapses in WT, C3−/− (F), and CD47−/− (G) mice (scale bars in E, F, and G are 50 μm). Insets show higher magnification of a single motor neuron with GAD65/67+ synapses (scale bar: 10 μm). (H) Quantification of GAD65/67+ synapses on the entire motor neuron soma for each genotype. Data points (in grey) on graphs show individual motor neurons; colored data points represent the average of four to five motor neurons from each mouse. Statistical comparison was performed across mouse averages. WT, N = 3 mice; C3−/−, N = 3; CD47−/−, N = 3. **P < 0.01, ***P < 0.001; ns: no significance; one-way ANOVA, post hoc Bonferroni’s test.