Fig. 10.
Diagrams of two intersegmental circuits whose dynamics have been explored using conductance-based models (Skinner and Mulloney, 1998; Jones et al., 2003). Each circuit shows two local pattern-generating circuits in two neighboring segments (An, An+1). An is an anterior segment, An+1 is the next posterior segment. In these models of local circuits, circles labeled 1A and 1B represent Int 1A and Int 1B neurons while the circle labeled 2A represents the pair of Int 2A neurons (see 2.2.2). Red-filled circles symbolize intersegmental inhibitory connections. Green-filled triangles symbolize intersegmental excitatory connections. These intersegmental connections are active whenever the local cell from which they originate is depolarized. Small black filled circles symbolize local graded inhibition. In both models, oscillations of potentials in these local cells depend on the kinetics of these graded synapses.