Figure 4. Both Doc2α and syt7 contribute to asynchronous release (AR) during train stimulation but have opposite effects on short-term plasticity at Schaffer collaterals.

(A) Representative excitatory postsynaptic currents (EPSCs) triggered by 20 Hz stimulus trains using WT, Doc2α^KO, syt7^KO, and EGTA-AM-treated neurons. The shaded gray areas indicate the tonic charge component that likely corresponds to AR. (B) The peak amplitude of each EPSC during the train was normalized to the first EPSC from WT (n = 12 recordings; from four independent litters), Doc2α^KO (n = 11; from three independent litters), syt7^KO (n = 10; from three independent litters), and EGTA-AM-treated neurons (n = 11, from three independent litters). Dots and error bars are mean ± standard error of the mean. (C) Bar graph showing the total tonic charge transfer (indicated by the gray areas in (A)), as a measure of cumulative AR from the train, from WT, Doc2α^KO, syt7^KO, and EGTA-AM-treated hippocampal slices. Error bars are mean ± 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 4—source data 1.