Figure 5.
Comparing neuronal activities and EPSPs in swimming and firing thresholds at RMPs. A, Reliable firing of a right-side dIN. B, Threshold tests of the dIN in A. C, dIN in A recorded with an electrode containing 2 mm QX314. *Period with 15 DC steps (500 pA, 10 ms at 50 Hz) used to facilitate the QX314 blockade of INa+. D, Overlapped phasic EPSPs on individual swimming cycles (gray lines) and their average (black). E, Activity of a right side cIN. F, Threshold tests for the cIN in E. G, cIN in E recorded with a QX314 electrode. H, Overlapped EPSPs in the cIN in G and the average. I, Average EPSP peaks plotted against thresholds at RMPs with a dashed identity line. Black circles above the identity line are from non-dINs with EPSP peaks below their firing thresholds. J, Firing liability indices plotted against the firing reliability in swimming. Gray circles are for dINs and black circles are for non-dINs in I and J. Dashed lines in C, D, G, and H mark thresholds revealed in B and F, respectively. r, Right; l, left; m.n., motor nerve.