Figure 2. Tonic release is reduced by disrupting C2A/RIM heterodimerization in low Ca²⁺.

(A) Representative traces of mEPSCs and mIPSCs recorded at 0 mM Ca²⁺ from indicated genotypes. (B, C) Averaged frequency and amplitude of the mEPSCs and mIPSCs. (D) Representative traces of mEPSCs and mIPSCs recorded at 1 mM Ca²⁺ from the same genotypes in (A). (E, F) Quantification of the mEPSC and mIPSC frequency and amplitude from the genotypes in (D). Data are mean ± SEM (##, p < 0.01, ###, p < 0.001, n.s., non-significant when compared to UNC-13L rescue; ***, p < 0.001 when compared to wild-type; one-way ANOVA). The number of worms analyzed for each genotype is indicated in the bar graphs. (G) Quantification of the mEPSC and mIPSC frequencies at various Ca²⁺ levels (0, 0.05, 0.1, and 1 mM) from wild-type (black) and unc-10(nu487 K77/79E) mutants (red). Data are mean ± SEM (***, p < 0.001, n.s., non-significant when compared to wild-type; student’s t-test).