Figure 4.

Retrograde inhibition of GABA release onto POMC cells. For each experiment, two stimuli were applied close together, as described in the text. AM 251 decreased the paired-pulse ratio from 0.81 ± 0.05 to 0.61 ± 0.04 (A; p < 0.001; n = 30). WIN 55,212-2 did not have a significant effect under normal calcium-buffering conditions (B; p = 0.09; n = 12) but increased the paired-pulse ratio from 0.80 ± 0.04 to 1.0 ± 0.11 when calcium was tightly buffered (C; p < 0.05; n = 6). The traces on the left show averages of three eIPSCs during the minute just before drug perfusion and three eIPSCs between 9 and 10 min in drug. The graphs on the right represent mean ± SEM. Error bars represent SEM.