Fig. 5.

The maximum opioid inhibition is greater in withdrawn slices after stimulation of adenylyl cyclase.a, Concentration response curve to DAMGO measuring the amplitude of the IPSC in the absence of forskolin. DAMGO caused an inhibition that was the same in control untreated and morphine-withdrawn slices. b, In the presence of forskolin and DPCPX, DAMGO caused a larger inhibition of the IPSC in morphine-withdrawn slices than in controls. The sensitivity to DAMGO was not changed, whereas the maximum inhibition was increased. The stimulus intensity was adjusted such that initial amplitude of the IPSC was between 400 and 600 pA in each group.