Fig. 2.
Current–voltage relationship of the OFQ inhibition. Superimposed traces of high-voltage-gated Ca2+channel currents are shown in the absence (A) and presence (B) of 100 nm OFQ. The currents were elicited by 100 msec voltage steps in the range of −45 to +30 mV from a holding potential of −60 mV at 3 sec intervals. The current–voltage relationships shown in C were obtained by plotting the peak current amplitudes in the absence (open circle) and presence (filled circles) of orphanin FQ (OFQ; 100 nm) as a function of the test pulse potential.