Figure 5.

Blockers of K⁺ conductances did not reduce the inhibitory effect of MOR agonist DAMGO (100 nm) on monosynaptic C-fiber-evoked EPSCs. Aa, Ba, Representative time courses of the amplitudes of evoked EPSCs showing no reduction of the inhibition by DAMGO in the presence of the inward rectifying K⁺ channel blockers Ba²⁺ (1 mm) and Cs⁺ (5 mm), respectively. Ab, Bb, Bar graphs illustrate no change in DAMGO action before and after application of Ba²⁺ and Cs⁺, respectively. Number of neurons tested: n = 5 for Ba²⁺, n = 3 for Cs⁺. n.s., not significant.