Figure 3.
MOR agonist DAMGO (10 μm) reduced the rate of ionomycin-induced mEPSCs in rat spinal lamina I neurons. A, Representative traces of mEPSC events (control), and mEPSCs, induced by 2 μm ionomycin, before, during, and after application of DAMGO, showing a reduction of ionomycin-induced mEPSCs (VHold = −70 mV). TTX (1 μm) and Cd2+ (200 μm) were included in the bath solution. B, Bar graph summarizes the mean mEPSC rates. C, Typical time course of the action of ionomycin (2 μm) and DAMGO on mEPSC rate. D, Bar graph shows the lacking effect of DAMGO on mEPSC amplitudes. Calibration: A, 50 pA, 1 s. Number of neurons tested: B, D, n = 6; **p < 0.01.