Figure 4.

μ- and κ-opioid receptors mediate inhibition of evoked release from POMC terminals. A, Plot of light-evoked IPSC amplitudes over time shows no effect of the DOR-selective agonist DPDPE (100 nm) and inhibition of IPSC amplitude by the MOR-selective agonist DAMGO (10 μm). The DAMGO-induced inhibition is reversed by application of the MOR-specific antagonist CTAP (500 nm). B, Representative traces taken during control and agonist treatment. C, The specific KOR agonist U69593 (500 nm) inhibited evoked IPSC amplitude and was reversed by the addition of nor-BNI (100 nm). D, Representative traces taken during control conditions and during U69593 treatment.