Fig. 4.

A, Effects of bath-applied amines on an AB–PD subnetwork isolated from all pyloric synaptic inputs. Descending modulatory inputs were kept intact. A1, Simultaneous recordings from the AB and PD neurons. The recordings shown in all panels are from a single preparation. Dopamine (DA), octopamine (Oct), and serotonin (5HT) induced fully reversible and reproducible changes in the subnetwork activity. The control oscillation trough membrane potential of both neurons is marked by arrowsin all panels. A2, Effects of the bath-applied amines on cycle frequency in the AB–PD subnetwork. Open bars, Control; filled bars, amine bath application.B, Effects of bath-applied amines on cycle frequency in an AB–2xPD subnetwork, with descending modulatory inputs intact. InA2 and B, data show the mean of five to eight different preparations ± SD. Cycle frequencies in 5HT and Oct (*) are significantly different from control and DA but not from each other.