Fig. 5.
Augmentation of IBTX-insensitive, Cd-sensitive current by 1-ethyl-2-benzimidazolinone (EBIO). A, left: representative Cd-sensitive current recorded in IBTX evoked by a 20-ms step from −65 to −25 mV before (gray) or during (black) application of 20 μM EBIO. B: current-voltage relationships for the step (left) and tail (right) currents before (closed symbols) or after (open symbols) application of EBIO (n = 6). C: half-activation (V1/2) and slope factor (k) of the conductance-voltage curve, obtained from tail currents, with and without EBIO (n = 6). D, left: responses to a 50-Hz, 1-s train of 1-ms pulses to +20 mV (Vhold = −60 mV) before (top) or during (bottom) application of EBIO. Right traces are expansions of the current evoked by the final step. E: expansion of boxed region in D. F: interstep currents following the 20th pulse in D. G: peak interstep currents, measured 1 ms before the next step, during 50- or 100-Hz stimulation (n = 6). NS, nonsignificant.