Figure 4.

Activation of the cAMP/PKA pathway induces additional MOR inhibition of GABA synaptic currents. A, Effect of the AC activator forskolin (10 μm) on IPSCs in a naive neuron (normal) and a neuron in a naive slice treated with forskolin and AACOCF3. B, Summarized data of normalized IPSC amplitude after treatment of naive slices with forskolin, with the cAMP analog 8-bromo-cAMP (100 μm), or with AACOCF3 plus forskolin or cAMP before and after addition of DAMGO. C, D, IPSC pairs and summarized data of effects of forskolin and 8-bromo-cAMP on PPR in naive slices (normal, C), and effects of DAMGO on PPR in naive slices treated with forskolin plus AACOCF3 (D). **p < 0.01. cAMP, 8-bromo-cAMP; Forsk, Forskolin. Calibration: 100 pA and 50 ms.