Fig. 3. The pyloric motor pattern of Pugettia producta is similar to that of other decapod species, though its expression is more highly dependent on the presence of modulatory inputs from anteriorly located sources. (A) In P. producta, the pyloric motor pattern strongly resembled that recorded in other decapod species, and consisted of alternating bursts of action potentials in the three core pyloric neuronal types: the pyloric dilator (PD), lateral pyloric (LP) and pyloric (PY) neurons, recorded on the lateral ventricular nerve (lvn). The ventricular dilator (VD) and inferior cardiac (IC) neurons, recorded on the medial ventricular nerve (mvn), fired weaker bursts that were more or less in phase with the bursts in the LP and PY neurons, respectively. (B) Blocking the stomatogastric nerve (stn), which provides the only neuronal input to the STG, with isotonic sucrose eliminated all pyloric bursting within 15 min in most preparations, as shown here. (C) When the sucrose was replaced with saline, so that normal conduction was restored in the stn, the complete pyloric pattern recovered within 2–3 min. 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).