Fig. 2.

Synchronous and asynchronous release competes for the same release machinery. (A) Recordings of the action potential and associated postsynaptic response for sample 10-ms intervals when sharing between synchronous and asynchronous was maximal. The synchronous component scored on the basis of the 1.5-ms window is indicated for each interval by an asterisk. (B) Intervals with total release corresponding to >80% of the maximal response (shown in Fig. 1B as dashed line) were used to compare the contributions by synchronous and asynchronous release during each 10-ms interval. The open symbols are the values for each of the numbered individual intervals shown in A and closed symbols represent the values for the intervals not shown in A. The distribution was best fit by linear regression to a line with a correlation coefficient of 0.81. (C) The slope values for each of 11 cell pairs are plotted against the total charge associated with each 10-s recording. The dashed line indicates a slope of −1. The average correlation coefficient of the linear fits (as shown in B) of the 11 pairs was 0.82 ± 0.05.