Figure 6.

Sensory epithelium of utricle stained with synaptic markers in WT and TSP1/2 mutants. Counts were statistically analyzed with a one-way ANOVA followed by Scheffe’s post hoc test. A – C, WT utricle stained with RIBEYE (A) and postsynaptic SHANK1 (B) at P29. Overlay view is shown in C. D – F, TSP1/2 double mutant utricle stained with presynaptic ribbon marker RIBEYE (D) and postsynaptic SHANK1 (E). Colocalization of both markers is shown in F. G, Synaptic ribbon counts per 40 μm² area of utricle in TSP1/2 KOs and WT animals. Ribbon numbers in TSP1/2 mutants were lower than WT (P = 0.001). H, Quantification of the postsynaptic marker SHANK1. No significant difference was observed between WT and TSP1/2 mutants. I, Average number of synapses determined by presynaptic RIBEYE that colocalized with postsynaptic SHANK1 per 40 μm² in WT and TSP1/2 mutant mice. Number of synapses was reduced in TSP1/2 mutants compared to WT (P = 0.000). Number of animals tested (n) per genotype and type of staining are indicated on the graphs. Scale bar in A is 10 μm and applies to B – F. Results are expressed as mean ± SEM. Significant differences are indicated by * for P < 0.05, ** for P < 0.01 or *** for P < 0.001.