The Pyloric Pattern of the Lobster (Panulirus interruptus) Stomatogastric Ganglion Comprises Two Phase-Maintaining Subsets

Abstract

The pyloric pattern approximately maintains phase over a three- tofivefold frequency range when the pattern is defined by the pacemakerburst beginning. However, in this reference frame certain patternelements maintain phase better than others, which suggestsphase-maintaining subgroups might exist. Reanalysis of these data inreference frames defined by each element shows the pattern containstwo groups of pattern elements within which phase is well maintainedbut between which maintenance is relatively poor. A third elementshows intermediate maintenance with each group. If ventriculardilator neuron burst beginning (VDB) is chosen as pattern beginning,all members of one group occur early in the pattern, all members ofthe other occur late in the pattern, and the intermediate elementoccurs between the groups. Thus, at least for phase maintenance, VDBis a “natural” pyloric pattern beginning. These results suggestfull description of complex patterns is best achieved by analysis inmany reference frames.