Leeches crawl on solid surfaces by sequential waves of elongation and contraction of their body. Each segmental ganglia contains a central pattern generator (CPG) that can generate fictive crawling ('crawling') when exposed to dopamine (DA). Our goal is to elucidate the role of intersegmental interactions on 'crawling' coordination. In this study we isolated chains of three ganglia and applied DA in three configurations: global DA application, or local DA to the anterior or posterior ganglion, leaving the other two untreated. 'Crawling' was monitored in each ganglion by extracellular recordings of a contraction phase motoneuron. Coordination across ganglia was assessed using cross-correlation index and phase lag. Global DA induced coordinated activity in all ganglia (similar firing frequency). Local DA generated 'crawling' in the treated ganglion and rhythmic activity in adjacent untreated ganglia; similar lag between treated and adjacent ganglia to global DA, but untreated ganglia showed null lag between them. Firing frequency decreased linearly from the treated ganglion. Thus, activation of a segmental CPG entrains activity both ways but does not activate untreated CPGs nor establishes an interganglionic lag. The results suggest a multilayered intersegmental connectivity: a basic layer transmits rhythmic activity without lag, while local CPG activation is required for autonomous oscillation and proper metachronal order.