Figure 8. Asynchronous release (AR) in Doc2α/syt7 double knockout (DKO) neurons: non-additive effects on AR indicate function through a common pathway.

All recordings were carried out using acute hippocampal slices, in CA1, as described in Figures 2 and 4. Data from all conditions except Doc2α/syt7 DKO are the same as shown in Figures 2 and 4 and. (A) Averaged traces of evoked excitatory postsynaptic currents (EPSCs) recorded from WT (n = 18 recordings; from five independent litters), Doc2αKO (n = 15; from four independent litters), Doc2α/syt7 DKO (n = 14; from four independent litters), and EGTA-AM-treated neurons (n = 20; from four independent litters). (B) Bar graph summarizing the slow EPSC charge values. Error bars are mean ± the standard error of the mean. One-way ANOVA, followed by Dunnett's test, was used to compare mutants against WT. ***p<0.001. Exact p-value for slow EPSC charge in syt7 KO = 0.43. (C) Representative EPSCs triggered by 20 Hz stimulus trains using WT and Doc2α/syt7 DKO (n = 15 recordings; from five independent litters) neurons. (D) AR in WT, Doc2αKO, syt7KO, Doc2α/syt7 DKO, and EGTA-AM-treated neurons was estimated by measuring the total tonic charge transfer during the 20 Hz stimulus train, as described in Figure 4C. Error bars are mean ± the standard error of the mean. One-way ANOVA, followed by Dunnett's test, was used to compare mutants against WT. ***p<0.001. All data, summary statistics, and p-values are listed in Figure 8—source data 1.

Figure 8—figure supplement 1. EGTA-AM phenocopies synaptic depression of phasic responses in Doc2α/syt7 double knockouts (DKOs), an intermediate phenotype between the single KOs.

Recordings of CA1 neurons in hippocampal slices were carried out as described in Figure 4. The peak amplitude of each excitatory postsynaptic current (EPSC) during 50 action potentials (APs) at 20 Hz was normalized to the first EPSC from Doc2α/syt7 DKO slices; for comparison, all other conditions were replotted from Figure 4.