FIGURE 2:

Deleting syb2 increases the amplitude of single synaptic vesicle fusion events measured with vGluT1-pHluorin. (A) Example fluorescence traces of vGluT1-pHluorin single synaptic vesicle fusion events detected during sparse stimulation (0.1–0.05 Hz, 20–25 APs). (B) Average fluorescence amplitude (ΔF) of single synaptic vesicle fusion events. Kruskall-Wallis test: p < 0.0001. Dunn’s multiple comparison’s test for 2 mM Ca²⁺: WT vs. Het, p < 0.0001; WT vs. syb2 KO, p < 0.0001. Dunn’s multiple comparison’s test for 8 mM Ca²⁺: WT vs. Het, p = 0.0754; WT vs. syb2 KO, p < 0.0001. WT 2 mM Ca²⁺ vs. WT 8 mM Ca²⁺, p < 0.0001. (C, D) Probability distributions of single synaptic vesicle amplitudes (bars) with a Gaussian mix model fit (straight red lines).