Fig. 4: DEC induced inward currents at −40 mV revealed by blocking SLO-1 K currents with 5 mM 4AP.

a Representative DEC biphasic holding currents, in the absence of 4AP, following the application of 10 µM DEC at −40 mV. Note that an inward (downward) current precedes the outward current. b Box-plot representing mean ± SE of the initial inward peak current (−35.2 ± 2 pA) and the subsequent peak outward current (180.8 ± 16.8 pA) following 10 µM DEC (n = 5 from five worms). c Application of 5 mM 4AP produces a steady inward current due to the blocking of the steady outward potassium current. The application of 3 µM DEC during the plateau of the 4AP effect produces a steady inward current. d Box-plot of the mean 3 µM DEC inward current during the plateau of the 4AP effect, −109.9 ± 12.6 pA (n = 7 muscles from five worms). e DEC concentration-dependent inward current-responses in the presence of 5 mM 4AP at a holding potential of −40 mV. f Plot of the DEC concentration-dependent inward current-responses in the presence of 5 mM 4AP, −40mV, EC₅₀ 39.1 ± 0.6 µM (n = 5 muscles from five worms; for some concentrations the SE plotted are smaller than represented points on the graph). g Application of 2APB (30 µM) as an inhibitor of TRP channels inhibits the inward DEC (30 µM) current seen in the presence of 5 mM 4AP. h Box-plot of the 30 µM DEC induced inward currents before (−620.9 ± 47 pA) and in the presence of 30 µM 2APB (−26.9 ± 4.7 pA) as an inhibitor of TRP channels (paired t-test, p = 0.0001; 95% confidence interval was −720 to −470; n = 7 from six worms).