3. Interpretation
The authors support their inferences well with detailed and logically conveyed observations. The only thing I am not totally convinced is the conclusion of overexpression of Doc2bDN and Doc2b6A mutants results in short-term depression after repetitive stimulation. It might be helpful to show the absolute data rather than only normalized ones for the “recovery” measurements in figure 5 and 8. Also, if the authors can give some more justifications of the data showing short-term depression rather than larger initial peak.