Fig. 7. When the anterior inputs were intact and the ongoing pyloric pattern was active, proctolin did not cause significant changes in cycle period, but it did cause significant changes in the relative phases of the pyloric pattern and in the burst duration of some neurons. (A) Recordings of control activity and activity when 10^–6 mol l^–1 proctolin was bath-applied to the STG. (B,C) Phase plots, showing two cycles of the pyloric pattern in control saline (B) and in the presence of proctolin (C). The LP and IC neuron bursts were each prolonged, starting at about the same phase, but continuing longer, in proctolin than in control saline. The burst of PY neurons started sooner in proctolin than in control saline. (D) Cycle period was not significantly changed by proctolin when the stn was intact. (E,F) Graphs of the spike frequency during bursts (E) and of burst duration (F) in control saline and in proctolin, showing that most parameters were not altered, but both LP and IC neuron bursts increased in duration. N=5 for all graphs. Bars indicate standard deviations. Nerves: mvn, medial ventricular nerve (recording action potentials of the VD and IC neurons); pdn, pyloric dilator nerve (recording action potentials of the PD neurons); lvn, lateral ventricular nerve (recording action potentials of the PD, LP and PY neurons).